21271886 has 4 divisors (see below), whose sum is σ = 31907832. Its totient is φ = 10635942.

The previous prime is 21271883. The next prime is 21271891. The reversal of 21271886 is 68817212.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21271883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5317970 + ... + 5317973.

It is an arithmetic number, because the mean of its divisors is an integer number (7976958).

Almost surely, 2^21271886 is an apocalyptic number.

21271886 is a deficient number, since it is larger than the sum of its proper divisors (10635946).

21271886 is a wasteful number, since it uses less digits than its factorization.

21271886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10635945.

The product of its digits is 10752, while the sum is 35.

The square root of 21271886 is about 4612.1454877313. The cubic root of 21271886 is about 277.0779711602.

The spelling of 21271886 in words is "twenty-one million, two hundred seventy-one thousand, eight hundred eighty-six".