21935538 has 48 divisors (see below), whose sum is σ = 51667200. Its totient is φ = 6700320.

The previous prime is 21935531. The next prime is 21935549. The reversal of 21935538 is 83553912.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21935531) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9568 + ... + 11636.

It is an arithmetic number, because the mean of its divisors is an integer number (1076400).

Almost surely, 2^21935538 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21935538, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25833600).

21935538 is an abundant number, since it is smaller than the sum of its proper divisors (29731662).

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

21935538 is a wasteful number, since it uses less digits than its factorization.

21935538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2127 (or 2124 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 21935538 is about 4683.5390464904. The cubic root of 21935538 is about 279.9299910004.

The spelling of 21935538 in words is "twenty-one million, nine hundred thirty-five thousand, five hundred thirty-eight".