21595938 has 64 divisors (see below), whose sum is σ = 54647040. Its totient is φ = 5536512.

The previous prime is 21595927. The next prime is 21595949. The reversal of 21595938 is 83959512.

It is an interprime number because it is at equal distance from previous prime (21595927) and next prime (21595949).

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 21595938.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19668 + ... + 20736.

It is an arithmetic number, because the mean of its divisors is an integer number (853860).

Almost surely, 2^21595938 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21595938, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27323520).

21595938 is an abundant number, since it is smaller than the sum of its proper divisors (33051102).

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

21595938 is a wasteful number, since it uses less digits than its factorization.

21595938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131.

The product of its digits is 97200, while the sum is 42.

The square root of 21595938 is about 4647.1429932809. The cubic root of 21595938 is about 278.4778713910.

The spelling of 21595938 in words is "twenty-one million, five hundred ninety-five thousand, nine hundred thirty-eight".