855664091520 has 768 divisors, whose sum is σ = 3226504881600. Its totient is φ = 192297369600.

The previous prime is 855664091509. The next prime is 855664091521. The reversal of 855664091520 is 25190466558.

It is a happy number.

It is a super-2 number, since 2×855664091520² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (855664091521) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1856104090 + ... + 1856104550.

Almost surely, 2^855664091520 is an apocalyptic number.

855664091520 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 855664091520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1613252440800).

855664091520 is an abundant number, since it is smaller than the sum of its proper divisors (2370840790080).

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

855664091520 is a wasteful number, since it uses less digits than its factorization.

855664091520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 787 (or 768 counting only the distinct ones).

The product of its (nonzero) digits is 2592000, while the sum is 51.

The spelling of 855664091520 in words is "eight hundred fifty-five billion, six hundred sixty-four million, ninety-one thousand, five hundred twenty".