21480279 has 8 divisors (see below), whose sum is σ = 30147840. Its totient is φ = 13566456.

The previous prime is 21480257. The next prime is 21480293. The reversal of 21480279 is 97208412.

It is a happy number.

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

It is not a de Polignac number, because 21480279 - 2⁵ = 21480247 is a prime.

It is a super-2 number, since 2×21480279² = 922804771835682, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21480209) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 188367 + ... + 188480.

It is an arithmetic number, because the mean of its divisors is an integer number (3768480).

Almost surely, 2^21480279 is an apocalyptic number.

21480279 is a deficient number, since it is larger than the sum of its proper divisors (8667561).

21480279 is a wasteful number, since it uses less digits than its factorization.

21480279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376869.

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 21480279 is about 4634.6821897515. The cubic root of 21480279 is about 277.9798434396.

The spelling of 21480279 in words is "twenty-one million, four hundred eighty thousand, two hundred seventy-nine".