31020023021 has 16 divisors (see below), whose sum is σ = 33561932208. Its totient is φ = 28500595200.

The previous prime is 31020023017. The next prime is 31020023057. The reversal of 31020023021 is 12032002013.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 2090775625 + 28929247396 = 45725^2 + 170086^2 .

It is a cyclic number.

It is not a de Polignac number, because 31020023021 - 2² = 31020023017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31020022987 and 31020023005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31020023621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3725555 + ... + 3733871.

It is an arithmetic number, because the mean of its divisors is an integer number (2097620763).

Almost surely, 2^31020023021 is an apocalyptic number.

It is an amenable number.

31020023021 is a deficient number, since it is larger than the sum of its proper divisors (2541909187).

31020023021 is a wasteful number, since it uses less digits than its factorization.

31020023021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9632.

The product of its (nonzero) digits is 72, while the sum is 14.

Adding to 31020023021 its reverse (12032002013), we get a palindrome (43052025034).

The spelling of 31020023021 in words is "thirty-one billion, twenty million, twenty-three thousand, twenty-one".