20781872296 has 16 divisors (see below), whose sum is σ = 38972468340. Its totient is φ = 10389214080.

The previous prime is 20781872239. The next prime is 20781872299. The reversal of 20781872296 is 69227818702.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20103269796 + 678602500 = 141786^2 + 26050^2 .

It is a super-2 number, since 2×20781872296² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20781872299) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163231 + ... + 261166.

Almost surely, 2^20781872296 is an apocalyptic number.

It is an amenable number.

20781872296 is a deficient number, since it is larger than the sum of its proper divisors (18190596044).

20781872296 is a wasteful number, since it uses less digits than its factorization.

20781872296 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430524 (or 430520 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 52.

The spelling of 20781872296 in words is "twenty billion, seven hundred eighty-one million, eight hundred seventy-two thousand, two hundred ninety-six".