15640643 has 2 divisors, whose sum is σ = 15640644. Its totient is φ = 15640642.

The previous prime is 15640637. The next prime is 15640649. The reversal of 15640643 is 34604651.

It is a happy number.

15640643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (15640637) and next prime (15640649).

It is an emirp because it is prime and its reverse (34604651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15640643 - 2⁴ = 15640627 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (15640649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7820321 + 7820322.

It is an arithmetic number, because the mean of its divisors is an integer number (7820322).

Almost surely, 2^15640643 is an apocalyptic number.

15640643 is a deficient number, since it is larger than the sum of its proper divisors (1).

15640643 is an equidigital number, since it uses as much as digits as its factorization.

15640643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 15640643 is about 3954.8252805908. The cubic root of 15640643 is about 250.0834015070.

The spelling of 15640643 in words is "fifteen million, six hundred forty thousand, six hundred forty-three".