21393698 has 4 divisors (see below), whose sum is σ = 32090550. Its totient is φ = 10696848.

The previous prime is 21393683. The next prime is 21393707. The reversal of 21393698 is 89639312.

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., 16540489 + 4853209 = 4067^2 + 2203^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5348423 + ... + 5348426.

Almost surely, 2^21393698 is an apocalyptic number.

21393698 is a deficient number, since it is larger than the sum of its proper divisors (10696852).

21393698 is a wasteful number, since it uses less digits than its factorization.

21393698 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10696851.

The product of its digits is 69984, while the sum is 41.

The square root of 21393698 is about 4625.3322042854. The cubic root of 21393698 is about 277.6058541593.

The spelling of 21393698 in words is "twenty-one million, three hundred ninety-three thousand, six hundred ninety-eight".