21942378 has 48 divisors (see below), whose sum is σ = 50712480. Its totient is φ = 6836832.

The previous prime is 21942377. The next prime is 21942379. The reversal of 21942378 is 87324912.

It is an interprime number because it is at equal distance from previous prime (21942377) and next prime (21942379).

It is not an unprimeable number, because it can be changed into a prime (21942377) 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, 28000 + ... + 28772.

It is an arithmetic number, because the mean of its divisors is an integer number (1056510).

Almost surely, 2^21942378 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21942378, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25356240).

21942378 is an abundant number, since it is smaller than the sum of its proper divisors (28770102).

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

21942378 is a wasteful number, since it uses less digits than its factorization.

21942378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 883 (or 880 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 21942378 is about 4684.2692066106. The cubic root of 21942378 is about 279.9590841574.

The spelling of 21942378 in words is "twenty-one million, nine hundred forty-two thousand, three hundred seventy-eight".