22018729 has 2 divisors, whose sum is σ = 22018730. Its totient is φ = 22018728.

The previous prime is 22018727. The next prime is 22018793. The reversal of 22018729 is 92781022.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21874329 + 144400 = 4677^2 + 380^2 .

It is a cyclic number.

It is not a de Polignac number, because 22018729 - 2¹ = 22018727 is a prime.

Together with 22018727, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 22018729.

It is not a weakly prime, because it can be changed into another prime (22018727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11009364 + 11009365.

It is an arithmetic number, because the mean of its divisors is an integer number (11009365).

Almost surely, 2^22018729 is an apocalyptic number.

It is an amenable number.

22018729 is a deficient number, since it is larger than the sum of its proper divisors (1).

22018729 is an equidigital number, since it uses as much as digits as its factorization.

22018729 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 22018729 is about 4692.4118531945. The cubic root of 22018729 is about 280.2834247465.

The spelling of 22018729 in words is "twenty-two million, eighteen thousand, seven hundred twenty-nine".