251888641 has 9 divisors (see below), whose sum is σ = 257186371. Its totient is φ = 246698824.

The previous prime is 251888633. The next prime is 251888653. The reversal of 251888641 is 146888152.

The square root of 251888641 is 15871.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 16573041 + 235315600 = 4071^2 + 15340^2 .

It is not a de Polignac number, because 251888641 - 2³ = 251888633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251888141) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 936255 + ... + 936523.

Almost surely, 2^251888641 is an apocalyptic number.

251888641 is the 15871-st square number.

251888641 is the 7936-th centered octagonal number.

It is an amenable number.

251888641 is a deficient number, since it is larger than the sum of its proper divisors (5297730).

251888641 is an frugal number, since it uses more digits than its factorization.

251888641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656 (or 328 counting only the distinct ones).

The product of its digits is 122880, while the sum is 43.

The cubic root of 251888641 is about 631.5429059135.

The spelling of 251888641 in words is "two hundred fifty-one million, eight hundred eighty-eight thousand, six hundred forty-one".