15124721 has 2 divisors, whose sum is σ = 15124722. Its totient is φ = 15124720.

The previous prime is 15124699. The next prime is 15124727. The reversal of 15124721 is 12742151.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15124321 + 400 = 3889^2 + 20^2 .

It is an emirp because it is prime and its reverse (12742151) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15124721 - 2⁶ = 15124657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15124727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7562360 + 7562361.

It is an arithmetic number, because the mean of its divisors is an integer number (7562361).

Almost surely, 2^15124721 is an apocalyptic number.

It is an amenable number.

15124721 is a deficient number, since it is larger than the sum of its proper divisors (1).

15124721 is an equidigital number, since it uses as much as digits as its factorization.

15124721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 560, while the sum is 23.

The square root of 15124721 is about 3889.0514267621. The cubic root of 15124721 is about 247.3028515378.

Adding to 15124721 its reverse (12742151), we get a palindrome (27866872).

The spelling of 15124721 in words is "fifteen million, one hundred twenty-four thousand, seven hundred twenty-one".