20661036780 has 24 divisors (see below), whose sum is σ = 57850903152. Its totient is φ = 5509609792.

The previous prime is 20661036757. The next prime is 20661036793. The reversal of 20661036780 is 8763016602.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 172175247 + ... + 172175366.

It is an arithmetic number, because the mean of its divisors is an integer number (2410454298).

Almost surely, 2^20661036780 is an apocalyptic number.

20661036780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20661036780 is an abundant number, since it is smaller than the sum of its proper divisors (37189866372).

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

20661036780 is a wasteful number, since it uses less digits than its factorization.

20661036780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 344350625 (or 344350623 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

The spelling of 20661036780 in words is "twenty billion, six hundred sixty-one million, thirty-six thousand, seven hundred eighty".