22172987 has 2 divisors, whose sum is σ = 22172988. Its totient is φ = 22172986.

The previous prime is 22172977. The next prime is 22173007. The reversal of 22172987 is 78927122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 22172987 - 2¹⁶ = 22107451 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 22172987.

It is not a weakly prime, because it can be changed into another prime (22172957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11086493 + 11086494.

It is an arithmetic number, because the mean of its divisors is an integer number (11086494).

Almost surely, 2^22172987 is an apocalyptic number.

22172987 is a deficient number, since it is larger than the sum of its proper divisors (1).

22172987 is an equidigital number, since it uses as much as digits as its factorization.

22172987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 28224, while the sum is 38.

The square root of 22172987 is about 4708.8201282275. The cubic root of 22172987 is about 280.9364352619.

The spelling of 22172987 in words is "twenty-two million, one hundred seventy-two thousand, nine hundred eighty-seven".