811641642 has 64 divisors (see below), whose sum is σ = 1997706240. Its totient is φ = 214546176.

The previous prime is 811641553. The next prime is 811641653. The reversal of 811641642 is 246146118.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32493 + ... + 51759.

It is an arithmetic number, because the mean of its divisors is an integer number (31214160).

Almost surely, 2^811641642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 811641642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (998853120).

811641642 is an abundant number, since it is smaller than the sum of its proper divisors (1186064598).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

811641642 is a wasteful number, since it uses less digits than its factorization.

811641642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19355.

The product of its digits is 9216, while the sum is 33.

The square root of 811641642 is about 28489.3250534301. The cubic root of 811641642 is about 932.7990753896.

The spelling of 811641642 in words is "eight hundred eleven million, six hundred forty-one thousand, six hundred forty-two".