21955455 has 40 divisors (see below), whose sum is σ = 41085792. Its totient is φ = 11195712.

The previous prime is 21955441. The next prime is 21955457. The reversal of 21955455 is 55455912.

21955455 is a `hidden beast` number, since 21 + 95 + 545 + 5 = 666.

It is not a de Polignac number, because 21955455 - 2¹⁵ = 21922687 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21955457) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8137 + ... + 10493.

Almost surely, 2^21955455 is an apocalyptic number.

21955455 is a deficient number, since it is larger than the sum of its proper divisors (19130337).

21955455 is a wasteful number, since it uses less digits than its factorization.

21955455 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2397 (or 2388 counting only the distinct ones).

The product of its digits is 45000, while the sum is 36.

The square root of 21955455 is about 4685.6648407670. The cubic root of 21955455 is about 280.0146888553.

The spelling of 21955455 in words is "twenty-one million, nine hundred fifty-five thousand, four hundred fifty-five".