21519794 has 4 divisors (see below), whose sum is σ = 32279694. Its totient is φ = 10759896.

The previous prime is 21519791. The next prime is 21519803. The reversal of 21519794 is 49791512.

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., 21114025 + 405769 = 4595^2 + 637^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21519791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5379947 + ... + 5379950.

Almost surely, 2^21519794 is an apocalyptic number.

21519794 is a deficient number, since it is larger than the sum of its proper divisors (10759900).

21519794 is a wasteful number, since it uses less digits than its factorization.

21519794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10759899.

The product of its digits is 22680, while the sum is 38.

The square root of 21519794 is about 4638.9431986175. The cubic root of 21519794 is about 278.1501957395.

The spelling of 21519794 in words is "twenty-one million, five hundred nineteen thousand, seven hundred ninety-four".