21281067 has 6 divisors (see below), whose sum is σ = 30739332. Its totient is φ = 14187372.

The previous prime is 21281053. The next prime is 21281069. The reversal of 21281067 is 76018212.

It is not a de Polignac number, because 21281067 - 2⁸ = 21280811 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21281067.

It is not an unprimeable number, because it can be changed into a prime (21281069) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1182273 + ... + 1182290.

It is an arithmetic number, because the mean of its divisors is an integer number (5123222).

Almost surely, 2^21281067 is an apocalyptic number.

21281067 is a deficient number, since it is larger than the sum of its proper divisors (9458265).

21281067 is a wasteful number, since it uses less digits than its factorization.

21281067 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2364569 (or 2364566 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 21281067 is about 4613.1406872108. The cubic root of 21281067 is about 277.1178279453.

Adding to 21281067 its reverse (76018212), we get a palindrome (97299279).

The spelling of 21281067 in words is "twenty-one million, two hundred eighty-one thousand, sixty-seven".