21439694 has 8 divisors (see below), whose sum is σ = 32184768. Its totient is φ = 10711440.

The previous prime is 21439673. The next prime is 21439699. The reversal of 21439694 is 49693412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21439699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 287 + ... + 6554.

It is an arithmetic number, because the mean of its divisors is an integer number (4023096).

Almost surely, 2^21439694 is an apocalyptic number.

21439694 is a deficient number, since it is larger than the sum of its proper divisors (10745074).

21439694 is a wasteful number, since it uses less digits than its factorization.

21439694 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8410.

The product of its digits is 46656, while the sum is 38.

The square root of 21439694 is about 4630.3017180309. The cubic root of 21439694 is about 277.8046606634.

The spelling of 21439694 in words is "twenty-one million, four hundred thirty-nine thousand, six hundred ninety-four".