21499056 has 60 divisors (see below), whose sum is σ = 60585408. Its totient is φ = 7116672.

The previous prime is 21499039. The next prime is 21499057. The reversal of 21499056 is 65099412.

It is a super-2 number, since 2×21499056² = 924418817782272, which contains 22 as substring.

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 21499056.

It is not an unprimeable number, because it can be changed into a prime (21499057) 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, 24481 + ... + 25343.

Almost surely, 2^21499056 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 21499056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30292704).

21499056 is an abundant number, since it is smaller than the sum of its proper divisors (39086352).

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

21499056 is a wasteful number, since it uses less digits than its factorization.

21499056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1050 (or 1041 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 21499056 is about 4636.7074524926. The cubic root of 21499056 is about 278.0608186036.

The spelling of 21499056 in words is "twenty-one million, four hundred ninety-nine thousand, fifty-six".