21693794 has 4 divisors (see below), whose sum is σ = 32540694. Its totient is φ = 10846896.

The previous prime is 21693787. The next prime is 21693799. The reversal of 21693794 is 49739612.

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., 13359025 + 8334769 = 3655^2 + 2887^2 .

It is a super-2 number, since 2×21693794² = 941241396228872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21693799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5423447 + ... + 5423450.

Almost surely, 2^21693794 is an apocalyptic number.

21693794 is a deficient number, since it is larger than the sum of its proper divisors (10846900).

21693794 is a wasteful number, since it uses less digits than its factorization.

21693794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10846899.

The product of its digits is 81648, while the sum is 41.

The square root of 21693794 is about 4657.6597127742. The cubic root of 21693794 is about 278.8978527501.

The spelling of 21693794 in words is "twenty-one million, six hundred ninety-three thousand, seven hundred ninety-four".