21255434 has 12 divisors (see below), whose sum is σ = 33023094. Its totient is φ = 10260432.

The previous prime is 21255431. The next prime is 21255439. The reversal of 21255434 is 43455212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 14417209 + 6838225 = 3797^2 + 2615^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21255431) 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, 4637 + ... + 8000.

Almost surely, 2^21255434 is an apocalyptic number.

21255434 is a deficient number, since it is larger than the sum of its proper divisors (11767660).

21255434 is a wasteful number, since it uses less digits than its factorization.

21255434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12697 (or 12668 counting only the distinct ones).

The product of its digits is 4800, while the sum is 26.

The square root of 21255434 is about 4610.3615910252. The cubic root of 21255434 is about 277.0065206318.

The spelling of 21255434 in words is "twenty-one million, two hundred fifty-five thousand, four hundred thirty-four".