20029273921 has 4 divisors (see below), whose sum is σ = 20368753200. Its totient is φ = 19689794644.

The previous prime is 20029273919. The next prime is 20029274029. The reversal of 20029273921 is 12937292002.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12937292002 = 2 ⋅6468646001.

It is a cyclic number.

It is not a de Polignac number, because 20029273921 - 2¹ = 20029273919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20029273721) 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, 169739551 + ... + 169739668.

It is an arithmetic number, because the mean of its divisors is an integer number (5092188300).

Almost surely, 2^20029273921 is an apocalyptic number.

It is an amenable number.

20029273921 is a deficient number, since it is larger than the sum of its proper divisors (339479279).

20029273921 is an equidigital number, since it uses as much as digits as its factorization.

20029273921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339479278.

The product of its (nonzero) digits is 27216, while the sum is 37.

The spelling of 20029273921 in words is "twenty billion, twenty-nine million, two hundred seventy-three thousand, nine hundred twenty-one".