21618696 has 64 divisors (see below), whose sum is σ = 62441280. Its totient is φ = 6164480.

The previous prime is 21618683. The next prime is 21618697. The reversal of 21618696 is 69681612.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (21618697) 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, 2080 + ... + 6896.

It is an arithmetic number, because the mean of its divisors is an integer number (975645).

Almost surely, 2^21618696 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 21618696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31220640).

21618696 is an abundant number, since it is smaller than the sum of its proper divisors (40822584).

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

21618696 is a wasteful number, since it uses less digits than its factorization.

21618696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4854 (or 4850 counting only the distinct ones).

The product of its digits is 31104, while the sum is 39.

The square root of 21618696 is about 4649.5909497503. The cubic root of 21618696 is about 278.5756579052.

The spelling of 21618696 in words is "twenty-one million, six hundred eighteen thousand, six hundred ninety-six".