21197025 has 48 divisors (see below), whose sum is σ = 40235520. Its totient is φ = 10929600.

The previous prime is 21197017. The next prime is 21197063. The reversal of 21197025 is 52079112.

It is not a de Polignac number, because 21197025 - 2³ = 21197017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 21197025.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 20419 + ... + 21431.

It is an arithmetic number, because the mean of its divisors is an integer number (838240).

Almost surely, 2^21197025 is an apocalyptic number.

21197025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21197025 is a deficient number, since it is larger than the sum of its proper divisors (19038495).

21197025 is a wasteful number, since it uses less digits than its factorization.

21197025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063 (or 1052 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 21197025 is about 4604.0226975983. The cubic root of 21197025 is about 276.7525539383.

The spelling of 21197025 in words is "twenty-one million, one hundred ninety-seven thousand, twenty-five".