31905645901 has 2 divisors, whose sum is σ = 31905645902. Its totient is φ = 31905645900.

The previous prime is 31905645869. The next prime is 31905645911. The reversal of 31905645901 is 10954650913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19612602025 + 12293043876 = 140045^2 + 110874^2 .

It is a cyclic number.

It is not a de Polignac number, because 31905645901 - 2⁵ = 31905645869 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31905645911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15952822950 + 15952822951.

It is an arithmetic number, because the mean of its divisors is an integer number (15952822951).

Almost surely, 2^31905645901 is an apocalyptic number.

It is an amenable number.

31905645901 is a deficient number, since it is larger than the sum of its proper divisors (1).

31905645901 is an equidigital number, since it uses as much as digits as its factorization.

31905645901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145800, while the sum is 43.

The spelling of 31905645901 in words is "thirty-one billion, nine hundred five million, six hundred forty-five thousand, nine hundred one".