251887649786879 has 2 divisors, whose sum is σ = 251887649786880. Its totient is φ = 251887649786878.

The previous prime is 251887649786867. The next prime is 251887649786909. The reversal of 251887649786879 is 978687946788152.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-251887649786879 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 251887649786791 and 251887649786800.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (251887649783879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 125943824893439 + 125943824893440.

It is an arithmetic number, because the mean of its divisors is an integer number (125943824893440).

Almost surely, 2^{251887649786879} is an apocalyptic number.

251887649786879 is a deficient number, since it is larger than the sum of its proper divisors (1).

251887649786879 is an equidigital number, since it uses as much as digits as its factorization.

251887649786879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163870801920, while the sum is 95.

The spelling of 251887649786879 in words is "two hundred fifty-one trillion, eight hundred eighty-seven billion, six hundred forty-nine million, seven hundred eighty-six thousand, eight hundred seventy-nine".