21080279 has 8 divisors (see below), whose sum is σ = 23738880. Its totient is φ = 18545400.

The previous prime is 21080261. The next prime is 21080317. The reversal of 21080279 is 97208012.

It is a happy number.

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 21080279 - 2¹⁶ = 21014743 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21080219) 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, 30569 + ... + 31250.

It is an arithmetic number, because the mean of its divisors is an integer number (2967360).

Almost surely, 2^21080279 is an apocalyptic number.

21080279 is a deficient number, since it is larger than the sum of its proper divisors (2658601).

21080279 is a wasteful number, since it uses less digits than its factorization.

21080279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61861.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 21080279 is about 4591.3264967763. The cubic root of 21080279 is about 276.2435319903.

The spelling of 21080279 in words is "twenty-one million, eighty thousand, two hundred seventy-nine".