31535228581 has 2 divisors, whose sum is σ = 31535228582. Its totient is φ = 31535228580.

The previous prime is 31535228573. The next prime is 31535228623. The reversal of 31535228581 is 18582253513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27741900481 + 3793328100 = 166559^2 + 61590^2 .

It is a cyclic number.

It is not a de Polignac number, because 31535228581 - 2³ = 31535228573 is a prime.

It is a super-2 number, since 2×31535228581² (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 (31535228281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15767614290 + 15767614291.

It is an arithmetic number, because the mean of its divisors is an integer number (15767614291).

Almost surely, 2^31535228581 is an apocalyptic number.

It is an amenable number.

31535228581 is a deficient number, since it is larger than the sum of its proper divisors (1).

31535228581 is an equidigital number, since it uses as much as digits as its factorization.

31535228581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288000, while the sum is 43.

The spelling of 31535228581 in words is "thirty-one billion, five hundred thirty-five million, two hundred twenty-eight thousand, five hundred eighty-one".