20905030666 has 16 divisors (see below), whose sum is σ = 33772329864. Its totient is φ = 9647714304.

The previous prime is 20905030633. The next prime is 20905030691. The reversal of 20905030666 is 66603050902.

It can be written as a sum of positive squares in 4 ways, for example, as 4952077641 + 15952953025 = 70371^2 + 126305^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 431946 + ... + 477898.

Almost surely, 2^20905030666 is an apocalyptic number.

20905030666 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20905030666 is a deficient number, since it is larger than the sum of its proper divisors (12867299198).

20905030666 is a wasteful number, since it uses less digits than its factorization.

20905030666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63465.

The product of its (nonzero) digits is 58320, while the sum is 37.

The spelling of 20905030666 in words is "twenty billion, nine hundred five million, thirty thousand, six hundred sixty-six".