251535026161 has 8 divisors (see below), whose sum is σ = 254424882600. Its totient is φ = 248646583680.

The previous prime is 251535026147. The next prime is 251535026177. The reversal of 251535026161 is 161620535152.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 24881907600 + 226653118561 = 157740^2 + 476081^2 .

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 251535026161 - 2⁷ = 251535026033 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 251535026161.

It is not an unprimeable number, because it can be changed into a prime (251535020161) 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, 6435 + ... + 709303.

It is an arithmetic number, because the mean of its divisors is an integer number (31803110325).

Almost surely, 2^251535026161 is an apocalyptic number.

It is an amenable number.

251535026161 is a deficient number, since it is larger than the sum of its proper divisors (2889856439).

251535026161 is an equidigital number, since it uses as much as digits as its factorization.

251535026161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 706979.

The product of its (nonzero) digits is 54000, while the sum is 37.

The spelling of 251535026161 in words is "two hundred fifty-one billion, five hundred thirty-five million, twenty-six thousand, one hundred sixty-one".