16640390401 has 2 divisors, whose sum is σ = 16640390402. Its totient is φ = 16640390400.

The previous prime is 16640390329. The next prime is 16640390413. The reversal of 16640390401 is 10409304661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16548249600 + 92140801 = 128640^2 + 9599^2 .

It is a cyclic number.

It is not a de Polignac number, because 16640390401 - 2¹¹ = 16640388353 is a prime.

It is not a weakly prime, because it can be changed into another prime (16640390491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8320195200 + 8320195201.

It is an arithmetic number, because the mean of its divisors is an integer number (8320195201).

Almost surely, 2^16640390401 is an apocalyptic number.

It is an amenable number.

16640390401 is a deficient number, since it is larger than the sum of its proper divisors (1).

16640390401 is an equidigital number, since it uses as much as digits as its factorization.

16640390401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 34.

The spelling of 16640390401 in words is "sixteen billion, six hundred forty million, three hundred ninety thousand, four hundred one".