21055434 has 16 divisors (see below), whose sum is σ = 42188160. Its totient is φ = 7005600.

The previous prime is 21055429. The next prime is 21055451. The reversal of 21055434 is 43455012.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 687 + ... + 6525.

It is an arithmetic number, because the mean of its divisors is an integer number (2636760).

Almost surely, 2^21055434 is an apocalyptic number.

21055434 is an abundant number, since it is smaller than the sum of its proper divisors (21132726).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21055434 is a wasteful number, since it uses less digits than its factorization.

21055434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6445.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 21055434 is about 4588.6200540032. The cubic root of 21055434 is about 276.1349633980.

The spelling of 21055434 in words is "twenty-one million, fifty-five thousand, four hundred thirty-four".