20662021161 has 20 divisors (see below), whose sum is σ = 30894707844. Its totient is φ = 13761640800.

The previous prime is 20662021157. The next prime is 20662021169. The reversal of 20662021161 is 16112026602.

20662021161 is a `hidden beast` number, since 2 + 0 + 6 + 620 + 21 + 16 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16833505536 + 3828515625 = 129744^2 + 61875^2 .

It is not a de Polignac number, because 20662021161 - 2² = 20662021157 is a prime.

It is a super-2 number, since 2×20662021161² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20662021169) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 34270 + ... + 206151.

Almost surely, 2^20662021161 is an apocalyptic number.

It is an amenable number.

20662021161 is a deficient number, since it is larger than the sum of its proper divisors (10232686683).

20662021161 is a wasteful number, since it uses less digits than its factorization.

20662021161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241494 (or 241485 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

Adding to 20662021161 its reverse (16112026602), we get a palindrome (36774047763).

The spelling of 20662021161 in words is "twenty billion, six hundred sixty-two million, twenty-one thousand, one hundred sixty-one".