21836685 has 32 divisors (see below), whose sum is σ = 37997568. Its totient is φ = 10644480.

The previous prime is 21836671. The next prime is 21836699. The reversal of 21836685 is 58663812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21836671) and next prime (21836699).

It is not a de Polignac number, because 21836685 - 2⁴ = 21836669 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 21540 + ... + 22530.

It is an arithmetic number, because the mean of its divisors is an integer number (1187424).

Almost surely, 2^21836685 is an apocalyptic number.

It is an amenable number.

21836685 is a deficient number, since it is larger than the sum of its proper divisors (16160883).

21836685 is a wasteful number, since it uses less digits than its factorization.

21836685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1125.

The product of its digits is 69120, while the sum is 39.

The square root of 21836685 is about 4672.9738925014. The cubic root of 21836685 is about 279.5088541245.

The spelling of 21836685 in words is "twenty-one million, eight hundred thirty-six thousand, six hundred eighty-five".