21255734 has 8 divisors (see below), whose sum is σ = 31968000. Its totient is φ = 10599736.

The previous prime is 21255733. The next prime is 21255743. The reversal of 21255734 is 43755212.

It is a happy number.

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

It is a junction number, because it is equal to n+sod(n) for n = 21255697 and 21255706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21255733) 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 in 3 ways as a sum of consecutive naturals, for example, 13109 + ... + 14640.

It is an arithmetic number, because the mean of its divisors is an integer number (3996000).

Almost surely, 2^21255734 is an apocalyptic number.

21255734 is a deficient number, since it is larger than the sum of its proper divisors (10712266).

21255734 is a wasteful number, since it uses less digits than its factorization.

21255734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28134.

The product of its digits is 8400, while the sum is 29.

The square root of 21255734 is about 4610.3941263194. The cubic root of 21255734 is about 277.0078238525.

The spelling of 21255734 in words is "twenty-one million, two hundred fifty-five thousand, seven hundred thirty-four".