31201220 has 24 divisors (see below), whose sum is σ = 65631384. Its totient is φ = 12459776.

The previous prime is 31201207. The next prime is 31201229. The reversal of 31201220 is 2210213.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 20164 + 31181056 = 142^2 + 5584^2 .

It is a super-2 number, since 2×31201220² = 1947032258976800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31201229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18242 + ... + 19878.

It is an arithmetic number, because the mean of its divisors is an integer number (2734641).

Almost surely, 2^31201220 is an apocalyptic number.

It is an amenable number.

31201220 is an abundant number, since it is smaller than the sum of its proper divisors (34430164).

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

31201220 is a wasteful number, since it uses less digits than its factorization.

31201220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2599 (or 2597 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 31201220 is about 5585.8052239583. The cubic root of 31201220 is about 314.8162865940.

Adding to 31201220 its reverse (2210213), we get a palindrome (33411433).

The spelling of 31201220 in words is "thirty-one million, two hundred one thousand, two hundred twenty".