251064660 has 192 divisors, whose sum is σ = 905232384. Its totient is φ = 50457600.

The previous prime is 251064641. The next prime is 251064661. The reversal of 251064660 is 66460152.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251064661) 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 63 ways as a sum of consecutive naturals, for example, 142344 + ... + 144096.

It is an arithmetic number, because the mean of its divisors is an integer number (4714752).

Almost surely, 2^251064660 is an apocalyptic number.

251064660 is a gapful number since it is divisible by the number (20) 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 251064660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (452616192).

251064660 is an abundant number, since it is smaller than the sum of its proper divisors (654167724).

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

251064660 is a wasteful number, since it uses less digits than its factorization.

251064660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1814 (or 1812 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 251064660 is about 15845.0200378542. The cubic root of 251064660 is about 630.8535168642.

The spelling of 251064660 in words is "two hundred fifty-one million, sixty-four thousand, six hundred sixty".