20661967356 has 48 divisors (see below), whose sum is σ = 49788254208. Its totient is φ = 6662232000.

The previous prime is 20661967321. The next prime is 20661967363. The reversal of 20661967356 is 65376916602.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20661967299 and 20661967308.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 938086 + ... + 959858.

It is an arithmetic number, because the mean of its divisors is an integer number (1037255296).

Almost surely, 2^20661967356 is an apocalyptic number.

It is an amenable number.

20661967356 is an abundant number, since it is smaller than the sum of its proper divisors (29126286852).

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

20661967356 is a wasteful number, since it uses less digits than its factorization.

20661967356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24362 (or 24360 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 51.

The spelling of 20661967356 in words is "twenty billion, six hundred sixty-one million, nine hundred sixty-seven thousand, three hundred fifty-six".