251572034640 has 40 divisors (see below), whose sum is σ = 779873308128. Its totient is φ = 67085875840.

The previous prime is 251572034591. The next prime is 251572034647. The reversal of 251572034640 is 46430275152.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×251572034640² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251572034647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 524108166 + ... + 524108645.

Almost surely, 2^251572034640 is an apocalyptic number.

251572034640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251572034640 is an abundant number, since it is smaller than the sum of its proper divisors (528301273488).

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

251572034640 is a wasteful number, since it uses less digits than its factorization.

251572034640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048216827 (or 1048216821 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 39.

The spelling of 251572034640 in words is "two hundred fifty-one billion, five hundred seventy-two million, thirty-four thousand, six hundred forty".