251217420 has 48 divisors (see below), whose sum is σ = 722426208. Its totient is φ = 65180160.

The previous prime is 251217409. The next prime is 251217433. The reversal of 251217420 is 24712152.

251217420 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×251217420² = 126220384222912800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54361 + ... + 58800.

It is an arithmetic number, because the mean of its divisors is an integer number (15050546).

Almost surely, 2^251217420 is an apocalyptic number.

251217420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251217420 is an abundant number, since it is smaller than the sum of its proper divisors (471208788).

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

251217420 is a wasteful number, since it uses less digits than its factorization.

251217420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113210 (or 113208 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 24.

The square root of 251217420 is about 15849.8397468239. The cubic root of 251217420 is about 630.9814382857.

Adding to 251217420 its reverse (24712152), we get a palindrome (275929572).

The spelling of 251217420 in words is "two hundred fifty-one million, two hundred seventeen thousand, four hundred twenty".