21694125 has 64 divisors (see below), whose sum is σ = 39626496. Its totient is φ = 10496000.

The previous prime is 21694069. The next prime is 21694133. The reversal of 21694125 is 52149612.

It is not a de Polignac number, because 21694125 - 2⁶ = 21694061 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21694092 and 21694101.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 261334 + ... + 261416.

It is an arithmetic number, because the mean of its divisors is an integer number (619164).

Almost surely, 2^21694125 is an apocalyptic number.

21694125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21694125 is the 2490-th nonagonal number.

It is an amenable number.

21694125 is a deficient number, since it is larger than the sum of its proper divisors (17932371).

21694125 is a wasteful number, since it uses less digits than its factorization.

21694125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 149 counting only the distinct ones).

The product of its digits is 4320, while the sum is 30.

The square root of 21694125 is about 4657.6952455050. The cubic root of 21694125 is about 278.8992712006.

The spelling of 21694125 in words is "twenty-one million, six hundred ninety-four thousand, one hundred twenty-five".