20661168513 has 16 divisors (see below), whose sum is σ = 28394663616. Its totient is φ = 13355569920.

The previous prime is 20661168509. The next prime is 20661168527. The reversal of 20661168513 is 31586116602.

It is not a de Polignac number, because 20661168513 - 2² = 20661168509 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20661168413) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 566868 + ... + 602213.

It is an arithmetic number, because the mean of its divisors is an integer number (1774666476).

Almost surely, 2^20661168513 is an apocalyptic number.

It is an amenable number.

20661168513 is a deficient number, since it is larger than the sum of its proper divisors (7733495103).

20661168513 is a wasteful number, since it uses less digits than its factorization.

20661168513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1169264.

The product of its (nonzero) digits is 51840, while the sum is 39.

The spelling of 20661168513 in words is "twenty billion, six hundred sixty-one million, one hundred sixty-eight thousand, five hundred thirteen".