251555740 has 12 divisors (see below), whose sum is σ = 528267096. Its totient is φ = 100622288.

The previous prime is 251555729. The next prime is 251555743. The reversal of 251555740 is 47555152.

It is a junction number, because it is equal to n+sod(n) for n = 251555696 and 251555705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251555743) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6288874 + ... + 6288913.

It is an arithmetic number, because the mean of its divisors is an integer number (44022258).

Almost surely, 2^251555740 is an apocalyptic number.

251555740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251555740 is an abundant number, since it is smaller than the sum of its proper divisors (276711356).

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

251555740 is a wasteful number, since it uses less digits than its factorization.

251555740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12577796 (or 12577794 counting only the distinct ones).

The product of its (nonzero) digits is 35000, while the sum is 34.

The square root of 251555740 is about 15860.5088190764. The cubic root of 251555740 is about 631.2645633996.

The spelling of 251555740 in words is "two hundred fifty-one million, five hundred fifty-five thousand, seven hundred forty".