15640563391 has 2 divisors, whose sum is σ = 15640563392. Its totient is φ = 15640563390.

The previous prime is 15640563353. The next prime is 15640563401. The reversal of 15640563391 is 19336504651.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15640563391 - 2¹³ = 15640555199 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15640563691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7820281695 + 7820281696.

It is an arithmetic number, because the mean of its divisors is an integer number (7820281696).

Almost surely, 2^15640563391 is an apocalyptic number.

15640563391 is a deficient number, since it is larger than the sum of its proper divisors (1).

15640563391 is an equidigital number, since it uses as much as digits as its factorization.

15640563391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 291600, while the sum is 43.

The spelling of 15640563391 in words is "fifteen billion, six hundred forty million, five hundred sixty-three thousand, three hundred ninety-one".