20621917166 has 16 divisors (see below), whose sum is σ = 30990340800. Its totient is φ = 10291821408.

The previous prime is 20621917163. The next prime is 20621917177. The reversal of 20621917166 is 66171912602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20621917163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3417440 + ... + 3423468.

It is an arithmetic number, because the mean of its divisors is an integer number (1936896300).

Almost surely, 2^20621917166 is an apocalyptic number.

20621917166 is a deficient number, since it is larger than the sum of its proper divisors (10368423634).

20621917166 is a wasteful number, since it uses less digits than its factorization.

20621917166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8923.

The product of its (nonzero) digits is 54432, while the sum is 41.

The spelling of 20621917166 in words is "twenty billion, six hundred twenty-one million, nine hundred seventeen thousand, one hundred sixty-six".