31428608 has 26 divisors (see below), whose sum is σ = 62857734. Its totient is φ = 15712256.

The previous prime is 31428601. The next prime is 31428611. The reversal of 31428608 is 80682413.

It can be written as a sum of positive squares in only one way, i.e., 28217344 + 3211264 = 5312^2 + 1792^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is not an unprimeable number, because it can be changed into a prime (31428601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260 + ... + 7932.

Almost surely, 2^31428608 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31428608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31428867).

31428608 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

31428608 is an frugal number, since it uses more digits than its factorization.

31428608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7697 (or 7675 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 31428608 is about 5606.1223675550. The cubic root of 31428608 is about 315.5792081134.

It can be divided in two parts, 3 and 1428608, that multiplied together give a palindrome (4285824).

The spelling of 31428608 in words is "thirty-one million, four hundred twenty-eight thousand, six hundred eight".