864800781 has 16 divisors (see below), whose sum is σ = 1242325056. Its totient is φ = 531945216.

The previous prime is 864800771. The next prime is 864800801. The reversal of 864800781 is 187008468.

It is not a de Polignac number, because 864800781 - 2⁵ = 864800749 is a prime.

It is a super-2 number, since 2×864800781² = 1495760781636419922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (864800771) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 126261 + ... + 132933.

It is an arithmetic number, because the mean of its divisors is an integer number (77645316).

Almost surely, 2^864800781 is an apocalyptic number.

It is an amenable number.

864800781 is a deficient number, since it is larger than the sum of its proper divisors (377524275).

864800781 is a wasteful number, since it uses less digits than its factorization.

864800781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10012.

The product of its (nonzero) digits is 86016, while the sum is 42.

The square root of 864800781 is about 29407.4953200710. The cubic root of 864800781 is about 952.7347904604.

The spelling of 864800781 in words is "eight hundred sixty-four million, eight hundred thousand, seven hundred eighty-one".