250399999921 has 2 divisors, whose sum is σ = 250399999922. Its totient is φ = 250399999920.

The previous prime is 250399999907. The next prime is 250400000027. The reversal of 250399999921 is 129999993052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198059711521 + 52340288400 = 445039^2 + 228780^2 .

It is a cyclic number.

It is not a de Polignac number, because 250399999921 - 2²⁵ = 250366445489 is a prime.

It is not a weakly prime, because it can be changed into another prime (250399999901) 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 as a sum of consecutive naturals, namely, 125199999960 + 125199999961.

It is an arithmetic number, because the mean of its divisors is an integer number (125199999961).

Almost surely, 2^250399999921 is an apocalyptic number.

It is an amenable number.

250399999921 is a deficient number, since it is larger than the sum of its proper divisors (1).

250399999921 is an equidigital number, since it uses as much as digits as its factorization.

250399999921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31886460, while the sum is 67.

The spelling of 250399999921 in words is "two hundred fifty billion, three hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred twenty-one".