21710579 has 4 divisors (see below), whose sum is σ = 23684280. Its totient is φ = 19736880.

The previous prime is 21710573. The next prime is 21710603. The reversal of 21710579 is 97501712.

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

It is a cyclic number.

It is not a de Polignac number, because 21710579 - 2²⁰ = 20662003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21710573) 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, 986834 + ... + 986855.

It is an arithmetic number, because the mean of its divisors is an integer number (5921070).

Almost surely, 2^21710579 is an apocalyptic number.

21710579 is a deficient number, since it is larger than the sum of its proper divisors (1973701).

21710579 is a wasteful number, since it uses less digits than its factorization.

21710579 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1973700.

The product of its (nonzero) digits is 4410, while the sum is 32.

The square root of 21710579 is about 4659.4612349498. The cubic root of 21710579 is about 278.9697641553.

The spelling of 21710579 in words is "twenty-one million, seven hundred ten thousand, five hundred seventy-nine".