257729391378 has 120 divisors (see below), whose sum is σ = 622637806032. Its totient is φ = 79648500096.

The previous prime is 257729391349. The next prime is 257729391421. The reversal of 257729391378 is 873193927752.

257729391378 is a `hidden beast` number, since 2 + 577 + 29 + 3 + 9 + 1 + 37 + 8 = 666.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 3095725 + ... + 3177887.

Almost surely, 2^257729391378 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257729391378, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311318903016).

257729391378 is an abundant number, since it is smaller than the sum of its proper divisors (364908414654).

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

257729391378 is a wasteful number, since it uses less digits than its factorization.

257729391378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82278 (or 82252 counting only the distinct ones).

The product of its digits is 40007520, while the sum is 63.

The spelling of 257729391378 in words is "two hundred fifty-seven billion, seven hundred twenty-nine million, three hundred ninety-one thousand, three hundred seventy-eight".