21432774 has 32 divisors (see below), whose sum is σ = 47149056. Its totient is φ = 6441120.

The previous prime is 21432751. The next prime is 21432781. The reversal of 21432774 is 47723412.

It is a Curzon number.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 7104 + ... + 9660.

It is an arithmetic number, because the mean of its divisors is an integer number (1473408).

Almost surely, 2^21432774 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21432774, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23574528).

21432774 is an abundant number, since it is smaller than the sum of its proper divisors (25716282).

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

21432774 is a wasteful number, since it uses less digits than its factorization.

21432774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2700.

The product of its digits is 9408, while the sum is 30.

The square root of 21432774 is about 4629.5544062037. The cubic root of 21432774 is about 277.7747688326.

The spelling of 21432774 in words is "twenty-one million, four hundred thirty-two thousand, seven hundred seventy-four".