21836660 has 48 divisors (see below), whose sum is σ = 49182336. Its totient is φ = 8122752.

The previous prime is 21836651. The next prime is 21836669. The reversal of 21836660 is 6663812.

It is an interprime number because it is at equal distance from previous prime (21836651) and next prime (21836669).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21836669) 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, 16379 + ... + 17661.

It is an arithmetic number, because the mean of its divisors is an integer number (1024632).

Almost surely, 2^21836660 is an apocalyptic number.

21836660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21836660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24591168).

21836660 is an abundant number, since it is smaller than the sum of its proper divisors (27345676).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21836660 is a wasteful number, since it uses less digits than its factorization.

21836660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1352 (or 1350 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 21836660 is about 4672.9712175446. The cubic root of 21836660 is about 279.5087474581.

The spelling of 21836660 in words is "twenty-one million, eight hundred thirty-six thousand, six hundred sixty".