21413724 has 24 divisors (see below), whose sum is σ = 50362368. Its totient is φ = 7081200.

The previous prime is 21413719. The next prime is 21413729. The reversal of 21413724 is 42731412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21413719) and next prime (21413729).

It is a junction number, because it is equal to n+sod(n) for n = 21413694 and 21413703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21413729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5502 + ... + 8549.

It is an arithmetic number, because the mean of its divisors is an integer number (2098432).

Almost surely, 2^21413724 is an apocalyptic number.

It is an amenable number.

21413724 is an abundant number, since it is smaller than the sum of its proper divisors (28948644).

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

21413724 is a wasteful number, since it uses less digits than its factorization.

21413724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14185 (or 14183 counting only the distinct ones).

The product of its digits is 1344, while the sum is 24.

The square root of 21413724 is about 4627.4965153958. The cubic root of 21413724 is about 277.6924466548.

The spelling of 21413724 in words is "twenty-one million, four hundred thirteen thousand, seven hundred twenty-four".