251252421 has 16 divisors (see below), whose sum is σ = 384810624. Its totient is φ = 142841664.

The previous prime is 251252413. The next prime is 251252423. The reversal of 251252421 is 124252152.

It is not a de Polignac number, because 251252421 - 2³ = 251252413 is a prime.

It is a super-2 number, since 2×251252421² = 126255558116722482, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 251252391 and 251252400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251252423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26230 + ... + 34503.

It is an arithmetic number, because the mean of its divisors is an integer number (24050664).

Almost surely, 2^251252421 is an apocalyptic number.

251252421 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

251252421 is a deficient number, since it is larger than the sum of its proper divisors (133558203).

251252421 is a wasteful number, since it uses less digits than its factorization.

251252421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60940.

The product of its digits is 1600, while the sum is 24.

The square root of 251252421 is about 15850.9438520234. The cubic root of 251252421 is about 631.0107408658.

The spelling of 251252421 in words is "two hundred fifty-one million, two hundred fifty-two thousand, four hundred twenty-one".