15273721 has 2 divisors, whose sum is σ = 15273722. Its totient is φ = 15273720.

The previous prime is 15273703. The next prime is 15273751. The reversal of 15273721 is 12737251.

It is the 1596-th star number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11799225 + 3474496 = 3435^2 + 1864^2 .

It is a cyclic number.

It is not a de Polignac number, because 15273721 - 2¹³ = 15265529 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15273721.

It is not a weakly prime, because it can be changed into another prime (15273751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7636860 + 7636861.

It is an arithmetic number, because the mean of its divisors is an integer number (7636861).

Almost surely, 2^15273721 is an apocalyptic number.

It is an amenable number.

15273721 is a deficient number, since it is larger than the sum of its proper divisors (1).

15273721 is an equidigital number, since it uses as much as digits as its factorization.

15273721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2940, while the sum is 28.

The square root of 15273721 is about 3908.1608206419. The cubic root of 15273721 is about 248.1122941422.

The spelling of 15273721 in words is "fifteen million, two hundred seventy-three thousand, seven hundred twenty-one".