21694608 has 80 divisors (see below), whose sum is σ = 67079040. Its totient is φ = 6673536.

The previous prime is 21694583. The next prime is 21694609. The reversal of 21694608 is 80649612.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21694609) 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, 3685 + ... + 7547.

It is an arithmetic number, because the mean of its divisors is an integer number (838488).

Almost surely, 2^21694608 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 21694608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33539520).

21694608 is an abundant number, since it is smaller than the sum of its proper divisors (45384432).

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

21694608 is a wasteful number, since it uses less digits than its factorization.

21694608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3893 (or 3881 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 21694608 is about 4657.7470948947. The cubic root of 21694608 is about 278.9013409983.

The spelling of 21694608 in words is "twenty-one million, six hundred ninety-four thousand, six hundred eight".