21620199 has 12 divisors (see below), whose sum is σ = 29113656. Its totient is φ = 14271408.

The previous prime is 21620197. The next prime is 21620227. The reversal of 21620199 is 99102612.

It is a happy number.

It is not a de Polignac number, because 21620199 - 2¹ = 21620197 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620197) 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, 57777 + ... + 58149.

It is an arithmetic number, because the mean of its divisors is an integer number (2426138).

Almost surely, 2^21620199 is an apocalyptic number.

21620199 is a deficient number, since it is larger than the sum of its proper divisors (7493457).

21620199 is an equidigital number, since it uses as much as digits as its factorization.

21620199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 654 (or 515 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 21620199 is about 4649.7525740624. The cubic root of 21620199 is about 278.5821135753.

The spelling of 21620199 in words is "twenty-one million, six hundred twenty thousand, one hundred ninety-nine".