21479207 has 4 divisors (see below), whose sum is σ = 21504960. Its totient is φ = 21453456.

The previous prime is 21479191. The next prime is 21479209. The reversal of 21479207 is 70297412.

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 21479207 - 2⁴ = 21479191 is a prime.

It is a super-2 number, since 2×21479207² = 922712666697698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21479209) 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, 11582 + ... + 13307.

It is an arithmetic number, because the mean of its divisors is an integer number (5376240).

Almost surely, 2^21479207 is an apocalyptic number.

21479207 is a deficient number, since it is larger than the sum of its proper divisors (25753).

21479207 is an equidigital number, since it uses as much as digits as its factorization.

21479207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25752.

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 21479207 is about 4634.5665385233. The cubic root of 21479207 is about 277.9752190529.

The spelling of 21479207 in words is "twenty-one million, four hundred seventy-nine thousand, two hundred seven".