21429255 has 16 divisors (see below), whose sum is σ = 34351200. Its totient is φ = 11407488.

The previous prime is 21429209. The next prime is 21429257. The reversal of 21429255 is 55292412.

It is not a de Polignac number, because 21429255 - 2⁷ = 21429127 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21429257) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 10021 + ... + 11969.

It is an arithmetic number, because the mean of its divisors is an integer number (2146950).

Almost surely, 2^21429255 is an apocalyptic number.

21429255 is a deficient number, since it is larger than the sum of its proper divisors (12921945).

21429255 is a wasteful number, since it uses less digits than its factorization.

21429255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2690.

The product of its digits is 7200, while the sum is 30.

The square root of 21429255 is about 4629.1743324269. The cubic root of 21429255 is about 277.7595655911.

The spelling of 21429255 in words is "twenty-one million, four hundred twenty-nine thousand, two hundred fifty-five".