21936486 has 64 divisors (see below), whose sum is σ = 53012736. Its totient is φ = 5961600.

The previous prime is 21936463. The next prime is 21936487. The reversal of 21936486 is 68463912.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21936487) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31401 + ... + 32091.

It is an arithmetic number, because the mean of its divisors is an integer number (828324).

Almost surely, 2^21936486 is an apocalyptic number.

21936486 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21936486, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26506368).

21936486 is an abundant number, since it is smaller than the sum of its proper divisors (31076250).

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

21936486 is a wasteful number, since it uses less digits than its factorization.

21936486 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757.

The product of its digits is 62208, while the sum is 39.

The square root of 21936486 is about 4683.6402509159. The cubic root of 21936486 is about 279.9340235708.

It can be divided in two parts, 21936 and 486, that added together give a palindrome (22422).

The spelling of 21936486 in words is "twenty-one million, nine hundred thirty-six thousand, four hundred eighty-six".