16640377685 has 16 divisors (see below), whose sum is σ = 20076151536. Its totient is φ = 13240693248.

The previous prime is 16640377681. The next prime is 16640377703. The reversal of 16640377685 is 58677304661.

It can be written as a sum of positive squares in 8 ways, for example, as 180257476 + 16460120209 = 13426^2 + 128297^2 .

It is a cyclic number.

It is not a de Polignac number, because 16640377685 - 2² = 16640377681 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16640377681) 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 in 15 ways as a sum of consecutive naturals, for example, 712859 + ... + 735831.

It is an arithmetic number, because the mean of its divisors is an integer number (1254759471).

Almost surely, 2^16640377685 is an apocalyptic number.

It is an amenable number.

16640377685 is a deficient number, since it is larger than the sum of its proper divisors (3435773851).

16640377685 is a wasteful number, since it uses less digits than its factorization.

16640377685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23752.

The product of its (nonzero) digits is 5080320, while the sum is 53.

The spelling of 16640377685 in words is "sixteen billion, six hundred forty million, three hundred seventy-seven thousand, six hundred eighty-five".