21586797 has 16 divisors (see below), whose sum is σ = 32460480. Its totient is φ = 14175216.

The previous prime is 21586739. The next prime is 21586837. The reversal of 21586797 is 79768512.

It is a de Polignac number, because none of the positive numbers 2^k-21586797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21586727) 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, 4158 + ... + 7775.

It is an arithmetic number, because the mean of its divisors is an integer number (2028780).

Almost surely, 2^21586797 is an apocalyptic number.

21586797 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21586797 is a deficient number, since it is larger than the sum of its proper divisors (10873683).

21586797 is a wasteful number, since it uses less digits than its factorization.

21586797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12009 (or 12003 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 21586797 is about 4646.1593816829. The cubic root of 21586797 is about 278.4385750279.

The spelling of 21586797 in words is "twenty-one million, five hundred eighty-six thousand, seven hundred ninety-seven".