21195550 has 24 divisors (see below), whose sum is σ = 39970656. Its totient is φ = 8360640.

The previous prime is 21195547. The next prime is 21195563. The reversal of 21195550 is 5559112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 747 + ... + 6553.

It is an arithmetic number, because the mean of its divisors is an integer number (1665444).

Almost surely, 2^21195550 is an apocalyptic number.

21195550 is a deficient number, since it is larger than the sum of its proper divisors (18775106).

21195550 is a wasteful number, since it uses less digits than its factorization.

21195550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5892 (or 5887 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 28.

The square root of 21195550 is about 4603.8625088071. The cubic root of 21195550 is about 276.7461344921.

The spelling of 21195550 in words is "twenty-one million, one hundred ninety-five thousand, five hundred fifty".