21694128 has 20 divisors (see below), whose sum is σ = 56043288. Its totient is φ = 7231360.

The previous prime is 21694069. The next prime is 21694133. The reversal of 21694128 is 82149612.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225933 + ... + 226028.

Almost surely, 2^21694128 is an apocalyptic number.

It is an amenable number.

21694128 is an abundant number, since it is smaller than the sum of its proper divisors (34349160).

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

21694128 is a wasteful number, since it uses less digits than its factorization.

21694128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451972 (or 451966 counting only the distinct ones).

The product of its digits is 6912, while the sum is 33.

The square root of 21694128 is about 4657.6955675527. The cubic root of 21694128 is about 278.8992840566.

The spelling of 21694128 in words is "twenty-one million, six hundred ninety-four thousand, one hundred twenty-eight".