21413616 has 80 divisors (see below), whose sum is σ = 63948288. Its totient is φ = 6048000.

The previous prime is 21413611. The next prime is 21413617. The reversal of 21413616 is 61631412.

It is a hoax number, since the sum of its digits (24) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (24).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21413611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33621 + ... + 34251.

Almost surely, 2^21413616 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 21413616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31974144).

21413616 is an abundant number, since it is smaller than the sum of its proper divisors (42534672).

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

21413616 is a wasteful number, since it uses less digits than its factorization.

21413616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 750 (or 744 counting only the distinct ones).

The product of its digits is 864, while the sum is 24.

The square root of 21413616 is about 4627.4848460044. The cubic root of 21413616 is about 277.6919798073.

The spelling of 21413616 in words is "twenty-one million, four hundred thirteen thousand, six hundred sixteen".