21793616 has 40 divisors (see below), whose sum is σ = 47054280. Its totient is φ = 9709056.

The previous prime is 21793613. The next prime is 21793619. The reversal of 21793616 is 61639712.

It is an interprime number because it is at equal distance from previous prime (21793613) and next prime (21793619).

It can be written as a sum of positive squares in 4 ways, for example, as 633616 + 21160000 = 796^2 + 4600^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21793613) 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, 4226 + ... + 7838.

It is an arithmetic number, because the mean of its divisors is an integer number (1176357).

Almost surely, 2^21793616 is an apocalyptic number.

21793616 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21793616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23527140).

21793616 is an abundant number, since it is smaller than the sum of its proper divisors (25260664).

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

21793616 is a wasteful number, since it uses less digits than its factorization.

21793616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3663 (or 3657 counting only the distinct ones).

The product of its digits is 13608, while the sum is 35.

The square root of 21793616 is about 4668.3633106261. The cubic root of 21793616 is about 279.3249725829.

The spelling of 21793616 in words is "twenty-one million, seven hundred ninety-three thousand, six hundred sixteen".