21992825 has 6 divisors (see below), whose sum is σ = 27271134. Its totient is φ = 17594240.

The previous prime is 21992819. The next prime is 21992833. The reversal of 21992825 is 52829912.

It can be written as a sum of positive squares in 3 ways, for example, as 583696 + 21409129 = 764^2 + 4627^2 .

It is not a de Polignac number, because 21992825 - 2¹⁴ = 21976441 is a prime.

It is a Duffinian 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, 439832 + ... + 439881.

It is an arithmetic number, because the mean of its divisors is an integer number (4545189).

Almost surely, 2^21992825 is an apocalyptic number.

21992825 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21992825 is a deficient number, since it is larger than the sum of its proper divisors (5278309).

21992825 is an equidigital number, since it uses as much as digits as its factorization.

21992825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 879723 (or 879718 counting only the distinct ones).

The product of its digits is 25920, while the sum is 38.

The square root of 21992825 is about 4689.6508398814. The cubic root of 21992825 is about 280.1734681895.

The spelling of 21992825 in words is "twenty-one million, nine hundred ninety-two thousand, eight hundred twenty-five".