22156405 has 8 divisors (see below), whose sum is σ = 26613432. Its totient is φ = 17707968.

The previous prime is 22156397. The next prime is 22156439. The reversal of 22156405 is 50465122.

22156405 = 1484² + 1485² + ... + 1493².

It can be written as a sum of positive squares in 4 ways, for example, as 1444804 + 20711601 = 1202^2 + 4551^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 22156405 - 2³ = 22156397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 22156405.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7387 + ... + 9943.

It is an arithmetic number, because the mean of its divisors is an integer number (3326679).

Almost surely, 2^22156405 is an apocalyptic number.

It is an amenable number.

22156405 is a deficient number, since it is larger than the sum of its proper divisors (4457027).

22156405 is a wasteful number, since it uses less digits than its factorization.

22156405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4295.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 22156405 is about 4707.0590606025. The cubic root of 22156405 is about 280.8663853143.

The spelling of 22156405 in words is "twenty-two million, one hundred fifty-six thousand, four hundred five".