21386897 has 8 divisors (see below), whose sum is σ = 24537216. Its totient is φ = 18260352.

The previous prime is 21386879. The next prime is 21386917. The reversal of 21386897 is 79868312.

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

It is a cyclic number.

It is not a de Polignac number, because 21386897 - 2²⁴ = 4609681 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21386857) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 3968 + ... + 7649.

It is an arithmetic number, because the mean of its divisors is an integer number (3067152).

Almost surely, 2^21386897 is an apocalyptic number.

It is an amenable number.

21386897 is a deficient number, since it is larger than the sum of its proper divisors (3150319).

21386897 is a wasteful number, since it uses less digits than its factorization.

21386897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11887.

The product of its digits is 145152, while the sum is 44.

The square root of 21386897 is about 4624.5969554114. The cubic root of 21386897 is about 277.5764343194.

The spelling of 21386897 in words is "twenty-one million, three hundred eighty-six thousand, eight hundred ninety-seven".