15640440677 has 2 divisors, whose sum is σ = 15640440678. Its totient is φ = 15640440676.

The previous prime is 15640440593. The next prime is 15640440679. The reversal of 15640440677 is 77604404651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10045251076 + 5595189601 = 100226^2 + 74801^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15640440677 is a prime.

Together with 15640440679, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15640440679) 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, 7820220338 + 7820220339.

It is an arithmetic number, because the mean of its divisors is an integer number (7820220339).

Almost surely, 2^15640440677 is an apocalyptic number.

It is an amenable number.

15640440677 is a deficient number, since it is larger than the sum of its proper divisors (1).

15640440677 is an equidigital number, since it uses as much as digits as its factorization.

15640440677 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 564480, while the sum is 44.

The spelling of 15640440677 in words is "fifteen billion, six hundred forty million, four hundred forty thousand, six hundred seventy-seven".