21281692 has 6 divisors (see below), whose sum is σ = 37242968. Its totient is φ = 10640844.

The previous prime is 21281683. The next prime is 21281707. The reversal of 21281692 is 29618212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2660208 + ... + 2660215.

Almost surely, 2^21281692 is an apocalyptic number.

It is an amenable number.

21281692 is a deficient number, since it is larger than the sum of its proper divisors (15961276).

21281692 is a wasteful number, since it uses less digits than its factorization.

21281692 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5320427 (or 5320425 counting only the distinct ones).

The product of its digits is 3456, while the sum is 31.

The square root of 21281692 is about 4613.2084279815. The cubic root of 21281692 is about 277.1205407940.

The spelling of 21281692 in words is "twenty-one million, two hundred eighty-one thousand, six hundred ninety-two".