21871634 has 8 divisors (see below), whose sum is σ = 32842368. Its totient is φ = 10924180.

The previous prime is 21871631. The next prime is 21871667. The reversal of 21871634 is 43617812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21871634.

It is not an unprimeable number, because it can be changed into a prime (21871631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3242 + ... + 7365.

It is an arithmetic number, because the mean of its divisors is an integer number (4105296).

Almost surely, 2^21871634 is an apocalyptic number.

21871634 is a deficient number, since it is larger than the sum of its proper divisors (10970734).

21871634 is a wasteful number, since it uses less digits than its factorization.

21871634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11640.

The product of its digits is 8064, while the sum is 32.

The square root of 21871634 is about 4676.7118790877. The cubic root of 21871634 is about 279.6578899960.

The spelling of 21871634 in words is "twenty-one million, eight hundred seventy-one thousand, six hundred thirty-four".