21393682 has 4 divisors (see below), whose sum is σ = 32090526. Its totient is φ = 10696840.

The previous prime is 21393653. The next prime is 21393683. The reversal of 21393682 is 28639312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 14055001 + 7338681 = 3749^2 + 2709^2 .

It is not an unprimeable number, because it can be changed into a prime (21393683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5348419 + ... + 5348422.

Almost surely, 2^21393682 is an apocalyptic number.

21393682 is a deficient number, since it is larger than the sum of its proper divisors (10696844).

21393682 is a wasteful number, since it uses less digits than its factorization.

21393682 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10696843.

The product of its digits is 15552, while the sum is 34.

The square root of 21393682 is about 4625.3304746796. The cubic root of 21393682 is about 277.6057849537.

The spelling of 21393682 in words is "twenty-one million, three hundred ninety-three thousand, six hundred eighty-two".