21694830 has 16 divisors (see below), whose sum is σ = 52067664. Its totient is φ = 5785280.

The previous prime is 21694817. The next prime is 21694837. The reversal of 21694830 is 3849612.

It is a junction number, because it is equal to n+sod(n) for n = 21694791 and 21694800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21694837) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 361551 + ... + 361610.

It is an arithmetic number, because the mean of its divisors is an integer number (3254229).

Almost surely, 2^21694830 is an apocalyptic number.

21694830 is an abundant number, since it is smaller than the sum of its proper divisors (30372834).

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

21694830 is a wasteful number, since it uses less digits than its factorization.

21694830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 723171.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 21694830 is about 4657.7709260976. The cubic root of 21694830 is about 278.9022923235.

The spelling of 21694830 in words is "twenty-one million, six hundred ninety-four thousand, eight hundred thirty".