21966025 has 6 divisors (see below), whose sum is σ = 27237902. Its totient is φ = 17572800.

The previous prime is 21966019. The next prime is 21966053. The reversal of 21966025 is 52066912.

It can be written as a sum of positive squares in 3 ways, for example, as 166464 + 21799561 = 408^2 + 4669^2 .

It is not a de Polignac number, because 21966025 - 2¹⁹ = 21441737 is a prime.

It is a super-3 number, since 3×21966025³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 439296 + ... + 439345.

Almost surely, 2^21966025 is an apocalyptic number.

21966025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21966025 is a deficient number, since it is larger than the sum of its proper divisors (5271877).

21966025 is an equidigital number, since it uses as much as digits as its factorization.

21966025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878651 (or 878646 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 21966025 is about 4686.7926132911. The cubic root of 21966025 is about 280.0596174074.

The spelling of 21966025 in words is "twenty-one million, nine hundred sixty-six thousand, twenty-five".