21204597 has 16 divisors (see below), whose sum is σ = 30522240. Its totient is φ = 13054272.

The previous prime is 21204587. The next prime is 21204607. The reversal of 21204597 is 79540212.

It is an interprime number because it is at equal distance from previous prime (21204587) and next prime (21204607).

It is not a de Polignac number, because 21204597 - 2¹¹ = 21202549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204587) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 3298 + ... + 7299.

It is an arithmetic number, because the mean of its divisors is an integer number (1907640).

Almost surely, 2^21204597 is an apocalyptic number.

It is an amenable number.

21204597 is a deficient number, since it is larger than the sum of its proper divisors (9317643).

21204597 is a wasteful number, since it uses less digits than its factorization.

21204597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10652.

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 21204597 is about 4604.8449485298. The cubic root of 21204597 is about 276.7855038587.

The spelling of 21204597 in words is "twenty-one million, two hundred four thousand, five hundred ninety-seven".