21655044 has 36 divisors (see below), whose sum is σ = 54952716. Its totient is φ = 7190208.

The previous prime is 21655043. The next prime is 21655063. The reversal of 21655044 is 44055612.

21655044 is a `hidden beast` number, since 2 + 1 + 655 + 0 + 4 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16646400 + 5008644 = 4080^2 + 2238^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a junction number, because it is equal to n+sod(n) for n = 21654999 and 21655017.

It is not an unprimeable number, because it can be changed into a prime (21655043) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9522 + ... + 11574.

Almost surely, 2^21655044 is an apocalyptic number.

It is an amenable number.

21655044 is an abundant number, since it is smaller than the sum of its proper divisors (33297672).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21655044 is a wasteful number, since it uses less digits than its factorization.

21655044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2356 (or 2351 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 21655044 is about 4653.4980391099. The cubic root of 21655044 is about 278.7316956617.

The spelling of 21655044 in words is "twenty-one million, six hundred fifty-five thousand, forty-four".