15368921 has 2 divisors, whose sum is σ = 15368922. Its totient is φ = 15368920.

The previous prime is 15368893. The next prime is 15368923. The reversal of 15368921 is 12986351.

15368921 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12355225 + 3013696 = 3515^2 + 1736^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15368921 is a prime.

Together with 15368923, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15368923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7684460 + 7684461.

It is an arithmetic number, because the mean of its divisors is an integer number (7684461).

Almost surely, 2^15368921 is an apocalyptic number.

15368921 is the 2096-th centered heptagonal number.

It is an amenable number.

15368921 is a deficient number, since it is larger than the sum of its proper divisors (1).

15368921 is an equidigital number, since it uses as much as digits as its factorization.

15368921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 35.

The square root of 15368921 is about 3920.3215429350. The cubic root of 15368921 is about 248.6267155049.

The spelling of 15368921 in words is "fifteen million, three hundred sixty-eight thousand, nine hundred twenty-one".