251523420540 has 48 divisors (see below), whose sum is σ = 804874947072. Its totient is φ = 57491067456.

The previous prime is 251523420527. The next prime is 251523420563. The reversal of 251523420540 is 45024325152.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 299432224 + ... + 299433063.

It is an arithmetic number, because the mean of its divisors is an integer number (16768228064).

Almost surely, 2^251523420540 is an apocalyptic number.

251523420540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251523420540 is an abundant number, since it is smaller than the sum of its proper divisors (553351526532).

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

251523420540 is a wasteful number, since it uses less digits than its factorization.

251523420540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598865306 (or 598865304 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 33.

Adding to 251523420540 its reverse (45024325152), we get a palindrome (296547745692).

The spelling of 251523420540 in words is "two hundred fifty-one billion, five hundred twenty-three million, four hundred twenty thousand, five hundred forty".