21499492 has 72 divisors (see below), whose sum is σ = 48045312. Its totient is φ = 8213760.

The previous prime is 21499483. The next prime is 21499501. The reversal of 21499492 is 29499412.

It is an interprime number because it is at equal distance from previous prime (21499483) and next prime (21499501).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 457413 + ... + 457459.

It is an arithmetic number, because the mean of its divisors is an integer number (667296).

Almost surely, 2^21499492 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21499492, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24022656).

21499492 is an abundant number, since it is smaller than the sum of its proper divisors (26545820).

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

21499492 is a wasteful number, since it uses less digits than its factorization.

21499492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137 (or 104 counting only the distinct ones).

The product of its digits is 46656, while the sum is 40.

The square root of 21499492 is about 4636.7544683755. The cubic root of 21499492 is about 278.0626982784.

The spelling of 21499492 in words is "twenty-one million, four hundred ninety-nine thousand, four hundred ninety-two".