20657161761 has 16 divisors (see below), whose sum is σ = 27911231040. Its totient is φ = 13587701760.

The previous prime is 20657161751. The next prime is 20657161783. The reversal of 20657161761 is 16716175602.

It is not a de Polignac number, because 20657161761 - 2¹⁰ = 20657160737 is a prime.

It is a super-2 number, since 2×20657161761² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20657161751) 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, 137541 + ... + 245421.

It is an arithmetic number, because the mean of its divisors is an integer number (1744451940).

Almost surely, 2^20657161761 is an apocalyptic number.

It is an amenable number.

20657161761 is a deficient number, since it is larger than the sum of its proper divisors (7254069279).

20657161761 is a wasteful number, since it uses less digits than its factorization.

20657161761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108736.

The product of its (nonzero) digits is 105840, while the sum is 42.

The spelling of 20657161761 in words is "twenty billion, six hundred fifty-seven million, one hundred sixty-one thousand, seven hundred sixty-one".