251421525642 has 16 divisors (see below), whose sum is σ = 574677772992. Its totient is φ = 71834721600.

The previous prime is 251421525629. The next prime is 251421525671. The reversal of 251421525642 is 246525124152.

It is a self number, because there is not a number n which added to its sum of digits gives 251421525642.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2993113359 + ... + 2993113442.

It is an arithmetic number, because the mean of its divisors is an integer number (35917360812).

Almost surely, 2^251421525642 is an apocalyptic number.

251421525642 is an abundant number, since it is smaller than the sum of its proper divisors (323256247350).

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

251421525642 is a wasteful number, since it uses less digits than its factorization.

251421525642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5986226813.

The product of its digits is 192000, while the sum is 39.

Adding to 251421525642 its reverse (246525124152), we get a palindrome (497946649794).

The spelling of 251421525642 in words is "two hundred fifty-one billion, four hundred twenty-one million, five hundred twenty-five thousand, six hundred forty-two".