21642160221523 has 4 divisors (see below), whose sum is σ = 21680601004008. Its totient is φ = 21603719439040.

The previous prime is 21642160221503. The next prime is 21642160221527. The reversal of 21642160221523 is 32512206124612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21642160221523 - 2³³ = 21633570286931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21642160221527) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19220390398 + ... + 19220391523.

It is an arithmetic number, because the mean of its divisors is an integer number (5420150251002).

Almost surely, 2^{21642160221523} is an apocalyptic number.

21642160221523 is a deficient number, since it is larger than the sum of its proper divisors (38440782485).

21642160221523 is an equidigital number, since it uses as much as digits as its factorization.

21642160221523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38440782484.

The product of its (nonzero) digits is 69120, while the sum is 37.

The spelling of 21642160221523 in words is "twenty-one trillion, six hundred forty-two billion, one hundred sixty million, two hundred twenty-one thousand, five hundred twenty-three".