20917253574721 has 8 divisors (see below), whose sum is σ = 23906170715264. Its totient is φ = 17928520948800.

The previous prime is 20917253574689. The next prime is 20917253574757. The reversal of 20917253574721 is 12747535271902.

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

It is not a de Polignac number, because 20917253574721 - 2⁵ = 20917253574689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20917253574781) 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, 45885645 + ... + 46339258.

It is an arithmetic number, because the mean of its divisors is an integer number (2988271339408).

Almost surely, 2^{20917253574721} is an apocalyptic number.

It is an amenable number.

20917253574721 is a deficient number, since it is larger than the sum of its proper divisors (2988917140543).

20917253574721 is an equidigital number, since it uses as much as digits as its factorization.

20917253574721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92257311.

The product of its (nonzero) digits is 7408800, while the sum is 55.

The spelling of 20917253574721 in words is "twenty trillion, nine hundred seventeen billion, two hundred fifty-three million, five hundred seventy-four thousand, seven hundred twenty-one".