31189354561 has 4 divisors (see below), whose sum is σ = 31914688432. Its totient is φ = 30464020692.

The previous prime is 31189354517. The next prime is 31189354579. The reversal of 31189354561 is 16545398113.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 31189354561 - 2⁷ = 31189354433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31189354061) 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, 362666871 + ... + 362666956.

It is an arithmetic number, because the mean of its divisors is an integer number (7978672108).

Almost surely, 2^31189354561 is an apocalyptic number.

It is an amenable number.

31189354561 is a deficient number, since it is larger than the sum of its proper divisors (725333871).

31189354561 is an equidigital number, since it uses as much as digits as its factorization.

31189354561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 725333870.

The product of its digits is 388800, while the sum is 46.

The spelling of 31189354561 in words is "thirty-one billion, one hundred eighty-nine million, three hundred fifty-four thousand, five hundred sixty-one".