22131220421 has 2 divisors, whose sum is σ = 22131220422. Its totient is φ = 22131220420.

The previous prime is 22131220403. The next prime is 22131220427. The reversal of 22131220421 is 12402213122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14716116100 + 7415104321 = 121310^2 + 86111^2 .

It is a cyclic number.

It is not a de Polignac number, because 22131220421 - 2¹⁸ = 22130958277 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22131220393 and 22131220402.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22131220427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11065610210 + 11065610211.

It is an arithmetic number, because the mean of its divisors is an integer number (11065610211).

Almost surely, 2^22131220421 is an apocalyptic number.

It is an amenable number.

22131220421 is a deficient number, since it is larger than the sum of its proper divisors (1).

22131220421 is an equidigital number, since it uses as much as digits as its factorization.

22131220421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 22131220421 its reverse (12402213122), we get a palindrome (34533433543).

The spelling of 22131220421 in words is "twenty-two billion, one hundred thirty-one million, two hundred twenty thousand, four hundred twenty-one".