20645517607571 has 8 divisors (see below), whose sum is σ = 20769945849744. Its totient is φ = 20521203262560.

The previous prime is 20645517607531. The next prime is 20645517607597. The reversal of 20645517607571 is 17570671554602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20645517607571 - 2²⁶ = 20645450498707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20645517607531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28110656 + ... + 28835741.

It is an arithmetic number, because the mean of its divisors is an integer number (2596243231218).

Almost surely, 2^{20645517607571} is an apocalyptic number.

20645517607571 is a deficient number, since it is larger than the sum of its proper divisors (124428242173).

20645517607571 is a wasteful number, since it uses less digits than its factorization.

20645517607571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56948581.

The product of its (nonzero) digits is 12348000, while the sum is 56.

The spelling of 20645517607571 in words is "twenty trillion, six hundred forty-five billion, five hundred seventeen million, six hundred seven thousand, five hundred seventy-one".