251027859821 has 2 divisors, whose sum is σ = 251027859822. Its totient is φ = 251027859820.

The previous prime is 251027859763. The next prime is 251027859829. The reversal of 251027859821 is 128958720152.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 162336468100 + 88691391721 = 402910^2 + 297811^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251027859821 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 251027859821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251027859829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125513929910 + 125513929911.

It is an arithmetic number, because the mean of its divisors is an integer number (125513929911).

Almost surely, 2^251027859821 is an apocalyptic number.

It is an amenable number.

251027859821 is a deficient number, since it is larger than the sum of its proper divisors (1).

251027859821 is an equidigital number, since it uses as much as digits as its factorization.

251027859821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 806400, while the sum is 50.

The spelling of 251027859821 in words is "two hundred fifty-one billion, twenty-seven million, eight hundred fifty-nine thousand, eight hundred twenty-one".