21354279 has 4 divisors (see below), whose sum is σ = 28472376. Its totient is φ = 14236184.

The previous prime is 21354251. The next prime is 21354293. The reversal of 21354279 is 97245312.

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 21354279 - 2⁵ = 21354247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21354079) 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, 3559044 + ... + 3559049.

It is an arithmetic number, because the mean of its divisors is an integer number (7118094).

Almost surely, 2^21354279 is an apocalyptic number.

21354279 is a deficient number, since it is larger than the sum of its proper divisors (7118097).

21354279 is an equidigital number, since it uses as much as digits as its factorization.

21354279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7118096.

The product of its digits is 15120, while the sum is 33.

The square root of 21354279 is about 4621.0690321613. The cubic root of 21354279 is about 277.4352482635.

The spelling of 21354279 in words is "twenty-one million, three hundred fifty-four thousand, two hundred seventy-nine".