21099024 has 30 divisors (see below), whose sum is σ = 59048366. Its totient is φ = 7032960.

The previous prime is 21099019. The next prime is 21099041. The reversal of 21099024 is 42099012.

It can be written as a sum of positive squares in only one way, i.e., 11289600 + 9809424 = 3360^2 + 3132^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 73117 + ... + 73404.

Almost surely, 2^21099024 is an apocalyptic number.

21099024 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21099024 is an abundant number, since it is smaller than the sum of its proper divisors (37949342).

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

21099024 is a wasteful number, since it uses less digits than its factorization.

21099024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146535 (or 146526 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21099024 is about 4593.3673922298. The cubic root of 21099024 is about 276.3253881320.

The spelling of 21099024 in words is "twenty-one million, ninety-nine thousand, twenty-four".