31528069021 has 2 divisors, whose sum is σ = 31528069022. Its totient is φ = 31528069020.

The previous prime is 31528069003. The next prime is 31528069091. The reversal of 31528069021 is 12096082513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23077863396 + 8450205625 = 151914^2 + 91925^2 .

It is a cyclic number.

It is not a de Polignac number, because 31528069021 - 2⁵ = 31528068989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31528069091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15764034510 + 15764034511.

It is an arithmetic number, because the mean of its divisors is an integer number (15764034511).

Almost surely, 2^31528069021 is an apocalyptic number.

It is an amenable number.

31528069021 is a deficient number, since it is larger than the sum of its proper divisors (1).

31528069021 is an equidigital number, since it uses as much as digits as its factorization.

31528069021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 37.

The spelling of 31528069021 in words is "thirty-one billion, five hundred twenty-eight million, sixty-nine thousand, twenty-one".