31905645905 has 16 divisors (see below), whose sum is σ = 43853788800. Its totient is φ = 21829420032.

The previous prime is 31905645901. The next prime is 31905645911. The reversal of 31905645905 is 50954650913.

It is not a de Polignac number, because 31905645905 - 2² = 31905645901 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31905645905.

It is not an unprimeable number, because it can be changed into a prime (31905645901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 999419 + ... + 1030848.

It is an arithmetic number, because the mean of its divisors is an integer number (2740861800).

Almost surely, 2^31905645905 is an apocalyptic number.

31905645905 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

31905645905 is a deficient number, since it is larger than the sum of its proper divisors (11948142895).

31905645905 is a wasteful number, since it uses less digits than its factorization.

31905645905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2030728.

The product of its (nonzero) digits is 729000, while the sum is 47.

The spelling of 31905645905 in words is "thirty-one billion, nine hundred five million, six hundred forty-five thousand, nine hundred five".