865249920 has 96 divisors (see below), whose sum is σ = 2987836020. Its totient is φ = 230731776.

The previous prime is 865249919. The next prime is 865249939. The reversal of 865249920 is 29942568.

It can be written as a sum of positive squares in 2 ways, for example, as 734193216 + 131056704 = 27096^2 + 11448^2 .

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 69349 + ... + 80868.

Almost surely, 2^865249920 is an apocalyptic number.

865249920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

865249920 is an abundant number, since it is smaller than the sum of its proper divisors (2122586100).

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

865249920 is a wasteful number, since it uses less digits than its factorization.

865249920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150242 (or 150227 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The square root of 865249920 is about 29415.1308003211. The cubic root of 865249920 is about 952.8996979176.

The spelling of 865249920 in words is "eight hundred sixty-five million, two hundred forty-nine thousand, nine hundred twenty".