861404091 has 4 divisors (see below), whose sum is σ = 1148538792. Its totient is φ = 574269392.

The previous prime is 861404087. The next prime is 861404111. The reversal of 861404091 is 190404168.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 861404091 - 2² = 861404087 is a prime.

It is not an unprimeable number, because it can be changed into a prime (861404041) 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, 143567346 + ... + 143567351.

It is an arithmetic number, because the mean of its divisors is an integer number (287134698).

Almost surely, 2^861404091 is an apocalyptic number.

861404091 is a deficient number, since it is larger than the sum of its proper divisors (287134701).

861404091 is a wasteful number, since it uses less digits than its factorization.

861404091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287134700.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 861404091 is about 29349.6863867401. The cubic root of 861404091 is about 951.4857972589.

The spelling of 861404091 in words is "eight hundred sixty-one million, four hundred four thousand, ninety-one".