251972610840 has 256 divisors, whose sum is σ = 889237440000. Its totient is φ = 63287391744.

The previous prime is 251972610829. The next prime is 251972610853. The reversal of 251972610840 is 48016279152.

251972610840 is a `hidden beast` number, since 2 + 519 + 7 + 26 + 108 + 4 + 0 = 666.

It is a super-2 number, since 2×251972610840² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3514471 + ... + 3585449.

It is an arithmetic number, because the mean of its divisors is an integer number (3473583750).

Almost surely, 2^251972610840 is an apocalyptic number.

251972610840 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 251972610840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (444618720000).

251972610840 is an abundant number, since it is smaller than the sum of its proper divisors (637264829160).

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

251972610840 is a wasteful number, since it uses less digits than its factorization.

251972610840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71191 (or 71181 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

Adding to 251972610840 its reverse (48016279152), we get a palindrome (299988889992).

The spelling of 251972610840 in words is "two hundred fifty-one billion, nine hundred seventy-two million, six hundred ten thousand, eight hundred forty".