21774955 has 12 divisors (see below), whose sum is σ = 26441856. Its totient is φ = 17214000.

The previous prime is 21774947. The next prime is 21774979. The reversal of 21774955 is 55947712.

It is not a de Polignac number, because 21774955 - 2³ = 21774947 is a prime.

It is a Duffinian 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 11 ways as a sum of consecutive naturals, for example, 113910 + ... + 114100.

It is an arithmetic number, because the mean of its divisors is an integer number (2203488).

Almost surely, 2^21774955 is an apocalyptic number.

21774955 is a deficient number, since it is larger than the sum of its proper divisors (4666901).

21774955 is an equidigital number, since it uses as much as digits as its factorization.

21774955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498 (or 347 counting only the distinct ones).

The product of its digits is 88200, while the sum is 40.

The square root of 21774955 is about 4666.3642163895. The cubic root of 21774955 is about 279.2452248903.

The spelling of 21774955 in words is "twenty-one million, seven hundred seventy-four thousand, nine hundred fifty-five".