21994038 has 64 divisors (see below), whose sum is σ = 54282240. Its totient is φ = 6544800.

The previous prime is 21994033. The next prime is 21994043. The reversal of 21994038 is 83049912.

It is an interprime number because it is at equal distance from previous prime (21994033) and next prime (21994043).

It is a junction number, because it is equal to n+sod(n) for n = 21993993 and 21994011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21994031) 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, 35931 + ... + 36537.

It is an arithmetic number, because the mean of its divisors is an integer number (848160).

Almost surely, 2^21994038 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21994038, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27141120).

21994038 is an abundant number, since it is smaller than the sum of its proper divisors (32288202).

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

21994038 is a wasteful number, since it uses less digits than its factorization.

21994038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 690 (or 684 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 21994038 is about 4689.7801654235. The cubic root of 21994038 is about 280.1786190234.

The spelling of 21994038 in words is "twenty-one million, nine hundred ninety-four thousand, thirty-eight".