20124253221 has 4 divisors (see below), whose sum is σ = 26832337632. Its totient is φ = 13416168812.

The previous prime is 20124253211. The next prime is 20124253267. The reversal of 20124253221 is 12235242102.

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 20124253221 - 2⁵ = 20124253189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20124253191 and 20124253200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20124253211) 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, 3354042201 + ... + 3354042206.

It is an arithmetic number, because the mean of its divisors is an integer number (6708084408).

Almost surely, 2^20124253221 is an apocalyptic number.

It is an amenable number.

20124253221 is a deficient number, since it is larger than the sum of its proper divisors (6708084411).

20124253221 is an equidigital number, since it uses as much as digits as its factorization.

20124253221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6708084410.

The product of its (nonzero) digits is 1920, while the sum is 24.

Adding to 20124253221 its reverse (12235242102), we get a palindrome (32359495323).

The spelling of 20124253221 in words is "twenty billion, one hundred twenty-four million, two hundred fifty-three thousand, two hundred twenty-one".