251220398 has 64 divisors (see below), whose sum is σ = 466712064. Its totient is φ = 99792000.

The previous prime is 251220391. The next prime is 251220433. The reversal of 251220398 is 893022152.

It is a happy number.

It is a super-2 number, since 2×251220398² = 126223376742556808, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251220391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1190513 + ... + 1190723.

It is an arithmetic number, because the mean of its divisors is an integer number (7292376).

Almost surely, 2^251220398 is an apocalyptic number.

251220398 is a deficient number, since it is larger than the sum of its proper divisors (215491666).

251220398 is a wasteful number, since it uses less digits than its factorization.

251220398 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 251220398 is about 15849.9336907130. The cubic root of 251220398 is about 630.9839315513.

The spelling of 251220398 in words is "two hundred fifty-one million, two hundred twenty thousand, three hundred ninety-eight".