251140289561 has 8 divisors (see below), whose sum is σ = 287068854144. Its totient is φ = 215224570080.

The previous prime is 251140289549. The next prime is 251140289579. The reversal of 251140289561 is 165982041152.

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

It is a cyclic number.

It is not a de Polignac number, because 251140289561 - 2³⁰ = 250066547737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (251140289531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3169340 + ... + 3247613.

It is an arithmetic number, because the mean of its divisors is an integer number (35883606768).

Almost surely, 2^251140289561 is an apocalyptic number.

It is an amenable number.

251140289561 is a deficient number, since it is larger than the sum of its proper divisors (35928564583).

251140289561 is an equidigital number, since it uses as much as digits as its factorization.

251140289561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6422551.

The product of its (nonzero) digits is 172800, while the sum is 44.

The spelling of 251140289561 in words is "two hundred fifty-one billion, one hundred forty million, two hundred eighty-nine thousand, five hundred sixty-one".