31525097581 has 2 divisors, whose sum is σ = 31525097582. Its totient is φ = 31525097580.

The previous prime is 31525097573. The next prime is 31525097609. The reversal of 31525097581 is 18579052513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26299108900 + 5225988681 = 162170^2 + 72291^2 .

It is a cyclic number.

It is not a de Polignac number, because 31525097581 - 2³ = 31525097573 is a prime.

It is a super-2 number, since 2×31525097581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31525097281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15762548790 + 15762548791.

It is an arithmetic number, because the mean of its divisors is an integer number (15762548791).

Almost surely, 2^31525097581 is an apocalyptic number.

It is an amenable number.

31525097581 is a deficient number, since it is larger than the sum of its proper divisors (1).

31525097581 is an equidigital number, since it uses as much as digits as its factorization.

31525097581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 378000, while the sum is 46.

The spelling of 31525097581 in words is "thirty-one billion, five hundred twenty-five million, ninety-seven thousand, five hundred eighty-one".