21694064 has 80 divisors (see below), whose sum is σ = 50592000. Its totient is φ = 9003456.

The previous prime is 21694061. The next prime is 21694069. The reversal of 21694064 is 46049612.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21694064.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21694061) 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, 323759 + ... + 323825.

It is an arithmetic number, because the mean of its divisors is an integer number (632400).

Almost surely, 2^21694064 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 21694064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25296000).

21694064 is an abundant number, since it is smaller than the sum of its proper divisors (28897936).

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

21694064 is an equidigital number, since it uses as much as digits as its factorization.

21694064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 135 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 21694064 is about 4657.6886971974. The cubic root of 21694064 is about 278.8990097954.

The spelling of 21694064 in words is "twenty-one million, six hundred ninety-four thousand, sixty-four".