21197546 has 8 divisors (see below), whose sum is σ = 31816260. Its totient is φ = 10592128.

The previous prime is 21197489. The next prime is 21197551. The reversal of 21197546 is 64579112.

It can be written as a sum of positive squares in 2 ways, for example, as 21114025 + 83521 = 4595^2 + 289^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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 3 ways as a sum of consecutive naturals, for example, 3320 + ... + 7308.

Almost surely, 2^21197546 is an apocalyptic number.

21197546 is a deficient number, since it is larger than the sum of its proper divisors (10618714).

21197546 is a wasteful number, since it uses less digits than its factorization.

21197546 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6648.

The product of its digits is 15120, while the sum is 35.

The square root of 21197546 is about 4604.0792782054. The cubic root of 21197546 is about 276.7548213461.

The spelling of 21197546 in words is "twenty-one million, one hundred ninety-seven thousand, five hundred forty-six".