30961985905 has 4 divisors (see below), whose sum is σ = 37154383092. Its totient is φ = 24769588720.

The previous prime is 30961985903. The next prime is 30961985959. The reversal of 30961985905 is 50958916903.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50958916903 = 449 ⋅113494247.

It can be written as a sum of positive squares in 2 ways, for example, as 3438180496 + 27523805409 = 58636^2 + 165903^2 .

It is not a de Polignac number, because 30961985905 - 2¹ = 30961985903 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30961985903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3096198586 + ... + 3096198595.

It is an arithmetic number, because the mean of its divisors is an integer number (9288595773).

Almost surely, 2^30961985905 is an apocalyptic number.

It is an amenable number.

30961985905 is a deficient number, since it is larger than the sum of its proper divisors (6192397187).

30961985905 is an equidigital number, since it uses as much as digits as its factorization.

30961985905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6192397186.

The product of its (nonzero) digits is 2624400, while the sum is 55.

The spelling of 30961985905 in words is "thirty billion, nine hundred sixty-one million, nine hundred eighty-five thousand, nine hundred five".