21947376 has 80 divisors (see below), whose sum is σ = 62460288. Its totient is φ = 6585600.

The previous prime is 21947371. The next prime is 21947383. The reversal of 21947376 is 67374912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21947371) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 103911 + ... + 104121.

Almost surely, 2^21947376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21947376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31230144).

21947376 is an abundant number, since it is smaller than the sum of its proper divisors (40512912).

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

21947376 is a wasteful number, since it uses less digits than its factorization.

21947376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430 (or 424 counting only the distinct ones).

The product of its digits is 63504, while the sum is 39.

The square root of 21947376 is about 4684.8026639337. The cubic root of 21947376 is about 279.9803387555.

The spelling of 21947376 in words is "twenty-one million, nine hundred forty-seven thousand, three hundred seventy-six".