15399974881 has 2 divisors, whose sum is σ = 15399974882. Its totient is φ = 15399974880.

The previous prime is 15399974879. The next prime is 15399974917. The reversal of 15399974881 is 18847999351.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8613510481 + 6786464400 = 92809^2 + 82380^2 .

It is a cyclic number.

It is not a de Polignac number, because 15399974881 - 2¹ = 15399974879 is a prime.

It is a super-2 number, since 2×15399974881² (a number of 21 digits) contains 22 as substring.

Together with 15399974879, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (15399974831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7699987440 + 7699987441.

It is an arithmetic number, because the mean of its divisors is an integer number (7699987441).

Almost surely, 2^15399974881 is an apocalyptic number.

It is an amenable number.

15399974881 is a deficient number, since it is larger than the sum of its proper divisors (1).

15399974881 is an equidigital number, since it uses as much as digits as its factorization.

15399974881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19595520, while the sum is 64.

The spelling of 15399974881 in words is "fifteen billion, three hundred ninety-nine million, nine hundred seventy-four thousand, eight hundred eighty-one".