20442347521 has 4 divisors (see below), whose sum is σ = 20445098544. Its totient is φ = 20439596500.

The previous prime is 20442347509. The next prime is 20442347567. The reversal of 20442347521 is 12574324402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20442347521 - 2⁵ = 20442347489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20442347621) 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, 1364335 + ... + 1379236.

It is an arithmetic number, because the mean of its divisors is an integer number (5111274636).

Almost surely, 2^20442347521 is an apocalyptic number.

It is an amenable number.

20442347521 is a deficient number, since it is larger than the sum of its proper divisors (2751023).

20442347521 is an equidigital number, since it uses as much as digits as its factorization.

20442347521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2751022.

The product of its (nonzero) digits is 53760, while the sum is 34.

The spelling of 20442347521 in words is "twenty billion, four hundred forty-two million, three hundred forty-seven thousand, five hundred twenty-one".