20656666506 has 64 divisors (see below), whose sum is σ = 50164945920. Its totient is φ = 5539000320.

The previous prime is 20656666501. The next prime is 20656666517. The reversal of 20656666506 is 60566665602.

It is a super-2 number, since 2×20656666506² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20656666501) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 35575 + ... + 206346.

It is an arithmetic number, because the mean of its divisors is an integer number (783827280).

Almost surely, 2^20656666506 is an apocalyptic number.

20656666506 is an abundant number, since it is smaller than the sum of its proper divisors (29508279414).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20656666506 is a wasteful number, since it uses less digits than its factorization.

20656666506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242059.

The product of its (nonzero) digits is 2332800, while the sum is 48.

The spelling of 20656666506 in words is "twenty billion, six hundred fifty-six million, six hundred sixty-six thousand, five hundred six".