811561955 has 16 divisors (see below), whose sum is σ = 1022505120. Its totient is φ = 617498112.

The previous prime is 811561943. The next prime is 811562027. The reversal of 811561955 is 559165118.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-811561955 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32054 + ... + 51483.

It is an arithmetic number, because the mean of its divisors is an integer number (63906570).

Almost surely, 2^811561955 is an apocalyptic number.

811561955 is a deficient number, since it is larger than the sum of its proper divisors (210943165).

811561955 is a wasteful number, since it uses less digits than its factorization.

811561955 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83638.

The product of its digits is 54000, while the sum is 41.

The square root of 811561955 is about 28487.9264777203. The cubic root of 811561955 is about 932.7685469771.

The spelling of 811561955 in words is "eight hundred eleven million, five hundred sixty-one thousand, nine hundred fifty-five".