251535516641 has 8 divisors (see below), whose sum is σ = 263152882944. Its totient is φ = 240179214880.

The previous prime is 251535516623. The next prime is 251535516667. The reversal of 251535516641 is 146615535152.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251535516641 is a prime.

It is a super-2 number, since 2×251535516641² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 251535516592 and 251535516601.

It is not an unprimeable number, because it can be changed into a prime (251535516691) 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, 65264165 + ... + 65268018.

It is an arithmetic number, because the mean of its divisors is an integer number (32894110368).

Almost surely, 2^251535516641 is an apocalyptic number.

It is an amenable number.

251535516641 is a deficient number, since it is larger than the sum of its proper divisors (11617366303).

251535516641 is a wasteful number, since it uses less digits than its factorization.

251535516641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130532271.

The product of its digits is 540000, while the sum is 44.

The spelling of 251535516641 in words is "two hundred fifty-one billion, five hundred thirty-five million, five hundred sixteen thousand, six hundred forty-one".