15919121 has 2 divisors, whose sum is σ = 15919122. Its totient is φ = 15919120.

The previous prime is 15919117. The next prime is 15919129. The reversal of 15919121 is 12191951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13608721 + 2310400 = 3689^2 + 1520^2 .

It is a cyclic number.

It is not a de Polignac number, because 15919121 - 2² = 15919117 is a prime.

It is not a weakly prime, because it can be changed into another prime (15919129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7959560 + 7959561.

It is an arithmetic number, because the mean of its divisors is an integer number (7959561).

Almost surely, 2^15919121 is an apocalyptic number.

It is an amenable number.

15919121 is a deficient number, since it is larger than the sum of its proper divisors (1).

15919121 is an equidigital number, since it uses as much as digits as its factorization.

15919121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 810, while the sum is 29.

The square root of 15919121 is about 3989.8773164096. The cubic root of 15919121 is about 251.5589043967.

The spelling of 15919121 in words is "fifteen million, nine hundred nineteen thousand, one hundred twenty-one".