15214721 has 2 divisors, whose sum is σ = 15214722. Its totient is φ = 15214720.

The previous prime is 15214697. The next prime is 15214729. The reversal of 15214721 is 12741251.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10758400 + 4456321 = 3280^2 + 2111^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15214721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15214729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7607360 + 7607361.

It is an arithmetic number, because the mean of its divisors is an integer number (7607361).

Almost surely, 2^15214721 is an apocalyptic number.

It is an amenable number.

15214721 is a deficient number, since it is larger than the sum of its proper divisors (1).

15214721 is an equidigital number, since it uses as much as digits as its factorization.

15214721 is an evil number, because the sum of its binary digits is even.

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

The square root of 15214721 is about 3900.6052094515. The cubic root of 15214721 is about 247.7924088783.

Adding to 15214721 its reverse (12741251), we get a palindrome (27955972).

The spelling of 15214721 in words is "fifteen million, two hundred fourteen thousand, seven hundred twenty-one".