15149921 has 4 divisors (see below), whose sum is σ = 15228612. Its totient is φ = 15071232.

The previous prime is 15149887. The next prime is 15149969. The reversal of 15149921 is 12994151.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3150625 + 11999296 = 1775^2 + 3464^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15149921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15149521) 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 in 3 ways as a sum of consecutive naturals, for example, 39056 + ... + 39441.

It is an arithmetic number, because the mean of its divisors is an integer number (3807153).

Almost surely, 2^15149921 is an apocalyptic number.

It is an amenable number.

15149921 is a deficient number, since it is larger than the sum of its proper divisors (78691).

15149921 is an equidigital number, since it uses as much as digits as its factorization.

15149921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78690.

The product of its digits is 3240, while the sum is 32.

The square root of 15149921 is about 3892.2899429513. The cubic root of 15149921 is about 247.4401229162.

The spelling of 15149921 in words is "fifteen million, one hundred forty-nine thousand, nine hundred twenty-one".