21355044 has 24 divisors (see below), whose sum is σ = 50574048. Its totient is φ = 7011840.

The previous prime is 21355039. The next prime is 21355057. The reversal of 21355044 is 44055312.

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, 12477 + ... + 14084.

It is an arithmetic number, because the mean of its divisors is an integer number (2107252).

Almost surely, 2^21355044 is an apocalyptic number.

It is an amenable number.

21355044 is an abundant number, since it is smaller than the sum of its proper divisors (29219004).

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

21355044 is a wasteful number, since it uses less digits than its factorization.

21355044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26635 (or 26633 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 21355044 is about 4621.1518044747. The cubic root of 21355044 is about 277.4385611894.

The spelling of 21355044 in words is "twenty-one million, three hundred fifty-five thousand, forty-four".