865777920 has 288 divisors, whose sum is σ = 3265167360. Its totient is φ = 191324160.

The previous prime is 865777909. The next prime is 865777931. The reversal of 865777920 is 29777568.

It is an interprime number because it is at equal distance from previous prime (865777909) and next prime (865777931).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 832761 + ... + 833799.

Almost surely, 2^865777920 is an apocalyptic number.

865777920 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 865777920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1632583680).

865777920 is an abundant number, since it is smaller than the sum of its proper divisors (2399389440).

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

865777920 is a wasteful number, since it uses less digits than its factorization.

865777920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101 (or 1087 counting only the distinct ones).

The product of its (nonzero) digits is 1481760, while the sum is 51.

The square root of 865777920 is about 29424.1044043825. The cubic root of 865777920 is about 953.0934872964.

The spelling of 865777920 in words is "eight hundred sixty-five million, seven hundred seventy-seven thousand, nine hundred twenty".