251651532 has 48 divisors (see below), whose sum is σ = 644700672. Its totient is φ = 75766080.

The previous prime is 251651507. The next prime is 251651539. The reversal of 251651532 is 235156152.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 251651532.

It is not an unprimeable number, because it can be changed into a prime (251651539) 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, 14653 + ... + 26795.

It is an arithmetic number, because the mean of its divisors is an integer number (13431264).

Almost surely, 2^251651532 is an apocalyptic number.

251651532 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 251651532, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322350336).

251651532 is an abundant number, since it is smaller than the sum of its proper divisors (393049140).

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

251651532 is a wasteful number, since it uses less digits than its factorization.

251651532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12318 (or 12316 counting only the distinct ones).

The product of its digits is 9000, while the sum is 30.

The square root of 251651532 is about 15863.5283591009. The cubic root of 251651532 is about 631.3446813899.

The spelling of 251651532 in words is "two hundred fifty-one million, six hundred fifty-one thousand, five hundred thirty-two".