861086440 has 32 divisors (see below), whose sum is σ = 1939792680. Its totient is φ = 344017152.

The previous prime is 861086419. The next prime is 861086453. The reversal of 861086440 is 44680168.

It can be written as a sum of positive squares in 4 ways, for example, as 594286884 + 266799556 = 24378^2 + 16334^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 861086440.

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, 21502 + ... + 46738.

Almost surely, 2^861086440 is an apocalyptic number.

It is an amenable number.

861086440 is an abundant number, since it is smaller than the sum of its proper divisors (1078706240).

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

861086440 is a wasteful number, since it uses less digits than its factorization.

861086440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26101 (or 26097 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 861086440 is about 29344.2743989351. The cubic root of 861086440 is about 951.3688263827.

The spelling of 861086440 in words is "eight hundred sixty-one million, eighty-six thousand, four hundred forty".