21099276 has 36 divisors (see below), whose sum is σ = 58183944. Its totient is φ = 6393600.

The previous prime is 21099187. The next prime is 21099277. The reversal of 21099276 is 67299012.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21099276.

It is not an unprimeable number, because it can be changed into a prime (21099277) 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, 26245 + ... + 27036.

Almost surely, 2^21099276 is an apocalyptic number.

It is an amenable number.

21099276 is an abundant number, since it is smaller than the sum of its proper divisors (37084668).

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

21099276 is a wasteful number, since it uses less digits than its factorization.

21099276 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53302 (or 53297 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 21099276 is about 4593.3948230040. The cubic root of 21099276 is about 276.3264882417.

The spelling of 21099276 in words is "twenty-one million, ninety-nine thousand, two hundred seventy-six".