15721967 has 2 divisors, whose sum is σ = 15721968. Its totient is φ = 15721966.

The previous prime is 15721921. The next prime is 15721997. The reversal of 15721967 is 76912751.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15721967 - 2¹⁸ = 15459823 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 15721967.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15721997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7860983 + 7860984.

It is an arithmetic number, because the mean of its divisors is an integer number (7860984).

Almost surely, 2^15721967 is an apocalyptic number.

15721967 is a deficient number, since it is larger than the sum of its proper divisors (1).

15721967 is an equidigital number, since it uses as much as digits as its factorization.

15721967 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 26460, while the sum is 38.

The square root of 15721967 is about 3965.0935676223. The cubic root of 15721967 is about 250.5160911997.

The spelling of 15721967 in words is "fifteen million, seven hundred twenty-one thousand, nine hundred sixty-seven".