856440090 has 48 divisors (see below), whose sum is σ = 2429178336. Its totient is φ = 207621600.

The previous prime is 856440083. The next prime is 856440199. The reversal of 856440090 is 90044658.

856440090 is a `hidden beast` number, since 8 + 5 + 644 + 0 + 0 + 9 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 431556 + ... + 433535.

It is an arithmetic number, because the mean of its divisors is an integer number (50607882).

Almost surely, 2^856440090 is an apocalyptic number.

856440090 is an abundant number, since it is smaller than the sum of its proper divisors (1572738246).

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

856440090 is a wasteful number, since it uses less digits than its factorization.

856440090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 865115 (or 865112 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 856440090 is about 29264.9976934904. The cubic root of 856440090 is about 949.6545706279.

The spelling of 856440090 in words is "eight hundred fifty-six million, four hundred forty thousand, ninety".