16664549761 has 4 divisors (see below), whose sum is σ = 17644817412. Its totient is φ = 15684282112.

The previous prime is 16664549723. The next prime is 16664549771. The reversal of 16664549761 is 16794546661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14957290000 + 1707259761 = 122300^2 + 41319^2 .

It is a cyclic number.

It is not a de Polignac number, because 16664549761 - 2²⁷ = 16530332033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16664549771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 490133800 + ... + 490133833.

It is an arithmetic number, because the mean of its divisors is an integer number (4411204353).

Almost surely, 2^16664549761 is an apocalyptic number.

It is an amenable number.

16664549761 is a deficient number, since it is larger than the sum of its proper divisors (980267651).

16664549761 is an equidigital number, since it uses as much as digits as its factorization.

16664549761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980267650.

The product of its digits is 6531840, while the sum is 55.

The spelling of 16664549761 in words is "sixteen billion, six hundred sixty-four million, five hundred forty-nine thousand, seven hundred sixty-one".