21630550 has 24 divisors (see below), whose sum is σ = 42352200. Its totient is φ = 8196480.

The previous prime is 21630541. The next prime is 21630551. The reversal of 21630550 is 5503612.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21630551) by changing a digit.

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, 10435 + ... + 12334.

It is an arithmetic number, because the mean of its divisors is an integer number (1764675).

Almost surely, 2^21630550 is an apocalyptic number.

21630550 is a deficient number, since it is larger than the sum of its proper divisors (20721650).

21630550 is a wasteful number, since it uses less digits than its factorization.

21630550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22800 (or 22795 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 22.

The square root of 21630550 is about 4650.8655108485. The cubic root of 21630550 is about 278.6265649607.

The spelling of 21630550 in words is "twenty-one million, six hundred thirty thousand, five hundred fifty".