21079549 has 8 divisors (see below), whose sum is σ = 21884760. Its totient is φ = 20279616.

The previous prime is 21079537. The next prime is 21079567. The reversal of 21079549 is 94597012.

It can be written as a sum of positive squares in 4 ways, for example, as 11449 + 21068100 = 107^2 + 4590^2 .

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 21079549 - 2²³ = 12690941 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 (21079519) 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, 8047 + ... + 10339.

It is an arithmetic number, because the mean of its divisors is an integer number (2735595).

Almost surely, 2^21079549 is an apocalyptic number.

21079549 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21079549 is a deficient number, since it is larger than the sum of its proper divisors (805211).

21079549 is a wasteful number, since it uses less digits than its factorization.

21079549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2639.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 21079549 is about 4591.2469983655. The cubic root of 21079549 is about 276.2403432262.

The spelling of 21079549 in words is "twenty-one million, seventy-nine thousand, five hundred forty-nine".