21116424 has 32 divisors (see below), whose sum is σ = 60333120. Its totient is φ = 6033216.

The previous prime is 21116411. The next prime is 21116453. The reversal of 21116424 is 42461112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21116424.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62679 + ... + 63014.

It is an arithmetic number, because the mean of its divisors is an integer number (1885410).

Almost surely, 2^21116424 is an apocalyptic number.

21116424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21116424 is an abundant number, since it is smaller than the sum of its proper divisors (39216696).

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

21116424 is a wasteful number, since it uses less digits than its factorization.

21116424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125709 (or 125705 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 21116424 is about 4595.2610371991. The cubic root of 21116424 is about 276.4013275159.

Adding to 21116424 its reverse (42461112), we get a palindrome (63577536).

The spelling of 21116424 in words is "twenty-one million, one hundred sixteen thousand, four hundred twenty-four".