31300020 has 90 divisors (see below), whose sum is σ = 98900802. Its totient is φ = 8286624.

The previous prime is 31300013. The next prime is 31300021. The reversal of 31300020 is 2000313.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 25040016 + 6260004 = 5004^2 + 2502^2 .

It is a tau number, because it is divible by the number of its divisors (90).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 31299975 and 31300011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31300021) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 225111 + ... + 225249.

Almost surely, 2^31300020 is an apocalyptic number.

31300020 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31300020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49450401).

31300020 is an abundant number, since it is smaller than the sum of its proper divisors (67600782).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31300020 is a wasteful number, since it uses less digits than its factorization.

31300020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 9.

The square root of 31300020 is about 5594.6420797045. The cubic root of 31300020 is about 315.1482295564.

Adding to 31300020 its reverse (2000313), we get a palindrome (33300333).

The spelling of 31300020 in words is "thirty-one million, three hundred thousand, twenty".