257821920 has 192 divisors, whose sum is σ = 927339840. Its totient is φ = 66852864.

The previous prime is 257821903. The next prime is 257821943. The reversal of 257821920 is 29128752.

257821920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159034 + ... + 160646.

It is an arithmetic number, because the mean of its divisors is an integer number (4829895).

Almost surely, 2^257821920 is an apocalyptic number.

257821920 is a gapful number since it is divisible by the number (20) 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 257821920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (463669920).

257821920 is an abundant number, since it is smaller than the sum of its proper divisors (669517920).

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

257821920 is a wasteful number, since it uses less digits than its factorization.

257821920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1674 (or 1660 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 257821920 is about 16056.8340590541. The cubic root of 257821920 is about 636.4631727543.

The spelling of 257821920 in words is "two hundred fifty-seven million, eight hundred twenty-one thousand, nine hundred twenty".