16172223421 has 2 divisors, whose sum is σ = 16172223422. Its totient is φ = 16172223420.

The previous prime is 16172223413. The next prime is 16172223439. The reversal of 16172223421 is 12432227161.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10190902500 + 5981320921 = 100950^2 + 77339^2 .

It is a cyclic number.

It is not a de Polignac number, because 16172223421 - 2³ = 16172223413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16172223451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8086111710 + 8086111711.

It is an arithmetic number, because the mean of its divisors is an integer number (8086111711).

Almost surely, 2^16172223421 is an apocalyptic number.

It is an amenable number.

16172223421 is a deficient number, since it is larger than the sum of its proper divisors (1).

16172223421 is an equidigital number, since it uses as much as digits as its factorization.

16172223421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 31.

The spelling of 16172223421 in words is "sixteen billion, one hundred seventy-two million, two hundred twenty-three thousand, four hundred twenty-one".