865961964 has 36 divisors (see below), whose sum is σ = 2501668624. Its totient is φ = 247417632.

The previous prime is 865961959. The next prime is 865961977. The reversal of 865961964 is 469169568.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 865961964.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1717927 + ... + 1718430.

Almost surely, 2^865961964 is an apocalyptic number.

865961964 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

865961964 is an abundant number, since it is smaller than the sum of its proper divisors (1635706660).

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

865961964 is a wasteful number, since it uses less digits than its factorization.

865961964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3436374 (or 3436369 counting only the distinct ones).

The product of its digits is 2799360, while the sum is 54.

The square root of 865961964 is about 29427.2316740804. The cubic root of 865961964 is about 953.1610175894.

The spelling of 865961964 in words is "eight hundred sixty-five million, nine hundred sixty-one thousand, nine hundred sixty-four".