811961811670 has 32 divisors (see below), whose sum is σ = 1570600780128. Its totient is φ = 301117352448.

The previous prime is 811961811637. The next prime is 811961811677. The reversal of 811961811670 is 76118169118.

It is a super-2 number, since 2×811961811670² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811961811677) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35632237 + ... + 35655016.

It is an arithmetic number, because the mean of its divisors is an integer number (49081274379).

Almost surely, 2^811961811670 is an apocalyptic number.

811961811670 is a deficient number, since it is larger than the sum of its proper divisors (758638968458).

811961811670 is a wasteful number, since it uses less digits than its factorization.

811961811670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71287344.

The product of its (nonzero) digits is 145152, while the sum is 49.

The spelling of 811961811670 in words is "eight hundred eleven billion, nine hundred sixty-one million, eight hundred eleven thousand, six hundred seventy".