21225479 has 4 divisors (see below), whose sum is σ = 23155080. Its totient is φ = 19295880.

The previous prime is 21225473. The next prime is 21225487. The reversal of 21225479 is 97452212.

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 21225479 - 2¹² = 21221383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21225473) 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, 964784 + ... + 964805.

It is an arithmetic number, because the mean of its divisors is an integer number (5788770).

Almost surely, 2^21225479 is an apocalyptic number.

21225479 is a deficient number, since it is larger than the sum of its proper divisors (1929601).

21225479 is a wasteful number, since it uses less digits than its factorization.

21225479 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1929600.

The product of its digits is 10080, while the sum is 32.

The square root of 21225479 is about 4607.1117850558. Note that the first 3 decimals coincide. The cubic root of 21225479 is about 276.8763322552.

The spelling of 21225479 in words is "twenty-one million, two hundred twenty-five thousand, four hundred seventy-nine".