251242434545 has 16 divisors (see below), whose sum is σ = 309475615680. Its totient is φ = 195700311744.

The previous prime is 251242434497. The next prime is 251242434571. The reversal of 251242434545 is 545434242152.

It is a cyclic number.

It is not a de Polignac number, because 251242434545 - 2¹⁶ = 251242369009 is a prime.

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, 1775015 + ... + 1911324.

It is an arithmetic number, because the mean of its divisors is an integer number (19342225980).

Almost surely, 2^251242434545 is an apocalyptic number.

It is an amenable number.

251242434545 is a deficient number, since it is larger than the sum of its proper divisors (58233181135).

251242434545 is a wasteful number, since it uses less digits than its factorization.

251242434545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3686704.

The product of its digits is 768000, while the sum is 41.

Adding to 251242434545 its reverse (545434242152), we get a palindrome (796676676697).

The spelling of 251242434545 in words is "two hundred fifty-one billion, two hundred forty-two million, four hundred thirty-four thousand, five hundred forty-five".