21625279 has 8 divisors (see below), whose sum is σ = 23918720. Its totient is φ = 19421856.

The previous prime is 21625243. The next prime is 21625297. The reversal of 21625279 is 97252612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21625279 - 2⁹ = 21624767 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 (21625229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21999 + ... + 22960.

It is an arithmetic number, because the mean of its divisors is an integer number (2989840).

Almost surely, 2^21625279 is an apocalyptic number.

21625279 is a deficient number, since it is larger than the sum of its proper divisors (2293441).

21625279 is a wasteful number, since it uses less digits than its factorization.

21625279 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45009.

The product of its digits is 15120, while the sum is 34.

The square root of 21625279 is about 4650.2988076037. The cubic root of 21625279 is about 278.6039309248.

It can be divided in two parts, 21625 and 279, that added together give a square (21904 = 148²).

The spelling of 21625279 in words is "twenty-one million, six hundred twenty-five thousand, two hundred seventy-nine".