21099696 has 20 divisors (see below), whose sum is σ = 54507672. Its totient is φ = 7033216.

The previous prime is 21099691. The next prime is 21099697. The reversal of 21099696 is 69699012.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21099691) 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 3 ways as a sum of consecutive naturals, for example, 219741 + ... + 219836.

Almost surely, 2^21099696 is an apocalyptic number.

It is an amenable number.

21099696 is an abundant number, since it is smaller than the sum of its proper divisors (33407976).

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

21099696 is a wasteful number, since it uses less digits than its factorization.

21099696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439588 (or 439582 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 42.

The square root of 21099696 is about 4593.4405405970. The cubic root of 21099696 is about 276.3283217383.

The spelling of 21099696 in words is "twenty-one million, ninety-nine thousand, six hundred ninety-six".