20351645635666 has 16 divisors (see below), whose sum is σ = 30999848619168. Its totient is φ = 10018851012000.

The previous prime is 20351645635661. The next prime is 20351645635723. The reversal of 20351645635666 is 66653654615302.

It is a super-2 number, since 2×20351645635666² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20351645635666.

It is not an unprimeable number, because it can be changed into a prime (20351645635661) 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, 121978660 + ... + 122145391.

It is an arithmetic number, because the mean of its divisors is an integer number (1937490538698).

Almost surely, 2^{20351645635666} is an apocalyptic number.

20351645635666 is a deficient number, since it is larger than the sum of its proper divisors (10648202983502).

20351645635666 is a wasteful number, since it uses less digits than its factorization.

20351645635666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244124697.

The product of its (nonzero) digits is 69984000, while the sum is 58.

The spelling of 20351645635666 in words is "twenty trillion, three hundred fifty-one billion, six hundred forty-five million, six hundred thirty-five thousand, six hundred sixty-six".