15121591 has 2 divisors, whose sum is σ = 15121592. Its totient is φ = 15121590.

The previous prime is 15121577. The next prime is 15121607. The reversal of 15121591 is 19512151.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15121591 - 2⁵ = 15121559 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15121531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7560795 + 7560796.

It is an arithmetic number, because the mean of its divisors is an integer number (7560796).

Almost surely, 2^15121591 is an apocalyptic number.

15121591 is a deficient number, since it is larger than the sum of its proper divisors (1).

15121591 is an equidigital number, since it uses as much as digits as its factorization.

15121591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 450, while the sum is 25.

The square root of 15121591 is about 3888.6489941881. The cubic root of 15121591 is about 247.2857909183.

The spelling of 15121591 in words is "fifteen million, one hundred twenty-one thousand, five hundred ninety-one".