811861385 has 8 divisors (see below), whose sum is σ = 984277896. Its totient is φ = 642792960.

The previous prime is 811861373. The next prime is 811861399. The reversal of 811861385 is 583168118.

It can be written as a sum of positive squares in 4 ways, for example, as 38576521 + 773284864 = 6211^2 + 27808^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 811861385 - 2¹⁸ = 811599241 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 836486 + ... + 837455.

It is an arithmetic number, because the mean of its divisors is an integer number (123034737).

Almost surely, 2^811861385 is an apocalyptic number.

It is an amenable number.

811861385 is a deficient number, since it is larger than the sum of its proper divisors (172416511).

811861385 is a wasteful number, since it uses less digits than its factorization.

811861385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1674043.

The product of its digits is 46080, while the sum is 41.

The square root of 811861385 is about 28493.1813773050. The cubic root of 811861385 is about 932.8832494722.

The spelling of 811861385 in words is "eight hundred eleven million, eight hundred sixty-one thousand, three hundred eighty-five".