257220640044 has 96 divisors (see below), whose sum is σ = 680764414400. Its totient is φ = 83965870080.

The previous prime is 257220639979. The next prime is 257220640073. The reversal of 257220640044 is 440046022752.

257220640044 is a `hidden beast` number, since 2 + 5 + 7 + 2 + 2 + 0 + 640 + 0 + 4 + 4 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 257220639990 and 257220640008.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1423404 + ... + 1593900.

Almost surely, 2^257220640044 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257220640044, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (340382207200).

257220640044 is an abundant number, since it is smaller than the sum of its proper divisors (423543774356).

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

257220640044 is a wasteful number, since it uses less digits than its factorization.

257220640044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170800 (or 170792 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 36.

Adding to 257220640044 its reverse (440046022752), we get a palindrome (697266662796).

The spelling of 257220640044 in words is "two hundred fifty-seven billion, two hundred twenty million, six hundred forty thousand, forty-four".