20666888408 has 8 divisors (see below), whose sum is σ = 38750415780. Its totient is φ = 10333444200.

The previous prime is 20666888377. The next prime is 20666888413. The reversal of 20666888408 is 80488866602.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1291680518 + ... + 1291680533.

Almost surely, 2^20666888408 is an apocalyptic number.

It is an amenable number.

20666888408 is a deficient number, since it is larger than the sum of its proper divisors (18083527372).

20666888408 is a wasteful number, since it uses less digits than its factorization.

20666888408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2583361057 (or 2583361053 counting only the distinct ones).

The product of its (nonzero) digits is 7077888, while the sum is 56.

The spelling of 20666888408 in words is "twenty billion, six hundred sixty-six million, eight hundred eighty-eight thousand, four hundred eight".