21079525 has 6 divisors (see below), whose sum is σ = 26138642. Its totient is φ = 16863600.

The previous prime is 21079519. The next prime is 21079537. The reversal of 21079525 is 52597012.

21079525 = 3246² + 3247².

It can be written as a sum of positive squares in 3 ways, for example, as 4870849 + 16208676 = 2207^2 + 4026^2 .

It is not a de Polignac number, because 21079525 - 2¹¹ = 21077477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 421566 + ... + 421615.

Almost surely, 2^21079525 is an apocalyptic number.

21079525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21079525 is the 3247-th centered square number.

It is an amenable number.

21079525 is a deficient number, since it is larger than the sum of its proper divisors (5059117).

21079525 is an equidigital number, since it uses as much as digits as its factorization.

21079525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843191 (or 843186 counting only the distinct ones).

The product of its (nonzero) digits is 6300, while the sum is 31.

The square root of 21079525 is about 4591.2443846957. The cubic root of 21079525 is about 276.2402383889.

The spelling of 21079525 in words is "twenty-one million, seventy-nine thousand, five hundred twenty-five".