20702772081 has 6 divisors (see below), whose sum is σ = 29904004130. Its totient is φ = 13801848048.

The previous prime is 20702772043. The next prime is 20702772109. The reversal of 20702772081 is 18027720702.

It can be written as a sum of positive squares in only one way, i.e., 20282317056 + 420455025 = 142416^2 + 20505^2 .

It is not a de Polignac number, because 20702772081 - 2⁷ = 20702771953 is a prime.

It is a super-2 number, since 2×20702772081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20702772011) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1150153996 + ... + 1150154013.

Almost surely, 2^20702772081 is an apocalyptic number.

It is an amenable number.

20702772081 is a deficient number, since it is larger than the sum of its proper divisors (9201232049).

20702772081 is a wasteful number, since it uses less digits than its factorization.

20702772081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2300308015 (or 2300308012 counting only the distinct ones).

The product of its (nonzero) digits is 21952, while the sum is 36.

The spelling of 20702772081 in words is "twenty billion, seven hundred two million, seven hundred seventy-two thousand, eighty-one".