21755650 has 48 divisors (see below), whose sum is σ = 47050560. Its totient is φ = 7329600.

The previous prime is 21755633. The next prime is 21755651. The reversal of 21755650 is 5655712.

It is not an unprimeable number, because it can be changed into a prime (21755651) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 20841 + ... + 21859.

It is an arithmetic number, because the mean of its divisors is an integer number (980220).

Almost surely, 2^21755650 is an apocalyptic number.

21755650 is an abundant number, since it is smaller than the sum of its proper divisors (25294910).

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

21755650 is a wasteful number, since it uses less digits than its factorization.

21755650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1099 (or 1094 counting only the distinct ones).

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 21755650 is about 4664.2952307932. The cubic root of 21755650 is about 279.1626771044.

The spelling of 21755650 in words is "twenty-one million, seven hundred fifty-five thousand, six hundred fifty".