15720643 has 2 divisors, whose sum is σ = 15720644. Its totient is φ = 15720642.

The previous prime is 15720641. The next prime is 15720659. The reversal of 15720643 is 34602751.

It is a weak prime.

It is an emirp because it is prime and its reverse (34602751) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15720643 - 2¹ = 15720641 is a prime.

Together with 15720641, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (15720641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7860321 + 7860322.

It is an arithmetic number, because the mean of its divisors is an integer number (7860322).

Almost surely, 2^15720643 is an apocalyptic number.

15720643 is a deficient number, since it is larger than the sum of its proper divisors (1).

15720643 is an equidigital number, since it uses as much as digits as its factorization.

15720643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 28.

The square root of 15720643 is about 3964.9266071392. The cubic root of 15720643 is about 250.5090587333.

The spelling of 15720643 in words is "fifteen million, seven hundred twenty thousand, six hundred forty-three".