251161944 has 128 divisors (see below), whose sum is σ = 731566080. Its totient is φ = 71014400.

The previous prime is 251161943. The next prime is 251162017. The reversal of 251161944 is 449161152.

It is a super-2 number, since 2×251161944² = 126164644227718272, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251161943) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 857062 + ... + 857354.

It is an arithmetic number, because the mean of its divisors is an integer number (5715360).

Almost surely, 2^251161944 is an apocalyptic number.

251161944 is a gapful number since it is divisible by the number (24) 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 251161944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (365783040).

251161944 is an abundant number, since it is smaller than the sum of its proper divisors (480404136).

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

251161944 is a wasteful number, since it uses less digits than its factorization.

251161944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521 (or 517 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 251161944 is about 15848.0896009582. The cubic root of 251161944 is about 630.9349886098.

The spelling of 251161944 in words is "two hundred fifty-one million, one hundred sixty-one thousand, nine hundred forty-four".