21606894 has 12 divisors (see below), whose sum is σ = 46814976. Its totient is φ = 7202292.

The previous prime is 21606869. The next prime is 21606899. The reversal of 21606894 is 49860612.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21606899) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 600174 + ... + 600209.

It is an arithmetic number, because the mean of its divisors is an integer number (3901248).

Almost surely, 2^21606894 is an apocalyptic number.

21606894 is an abundant number, since it is smaller than the sum of its proper divisors (25208082).

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

21606894 is a wasteful number, since it uses less digits than its factorization.

21606894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1200391 (or 1200388 counting only the distinct ones).

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

The square root of 21606894 is about 4648.3216325896. The cubic root of 21606894 is about 278.5249556739.

It can be divided in two parts, 21606 and 894, that added together give a square (22500 = 150²).

The spelling of 21606894 in words is "twenty-one million, six hundred six thousand, eight hundred ninety-four".