31023000021 has 16 divisors (see below), whose sum is σ = 44567659136. Its totient is φ = 19081728576.

The previous prime is 31022999993. The next prime is 31023000023. The reversal of 31023000021 is 12000032013.

It is a happy number.

It is not a de Polignac number, because 31023000021 - 2¹³ = 31022991829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 31022999970 and 31023000006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31023000023) 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, 113665 + ... + 273798.

It is an arithmetic number, because the mean of its divisors is an integer number (2785478696).

Almost surely, 2^31023000021 is an apocalyptic number.

It is an amenable number.

31023000021 is a deficient number, since it is larger than the sum of its proper divisors (13544659115).

31023000021 is a wasteful number, since it uses less digits than its factorization.

31023000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389532.

The product of its (nonzero) digits is 36, while the sum is 12.

Adding to 31023000021 its reverse (12000032013), we get a palindrome (43023032034).

The spelling of 31023000021 in words is "thirty-one billion, twenty-three million, twenty-one", and thus it is an aban number and an uban number.