21274134 has 36 divisors (see below), whose sum is σ = 49679604. Its totient is φ = 6055728.

The previous prime is 21274133. The next prime is 21274159. The reversal of 21274134 is 43147212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21274133) 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 17 ways as a sum of consecutive naturals, for example, 78952 + ... + 79220.

It is an arithmetic number, because the mean of its divisors is an integer number (1379989).

Almost surely, 2^21274134 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21274134, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24839802).

21274134 is an abundant number, since it is smaller than the sum of its proper divisors (28405470).

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

21274134 is an equidigital number, since it uses as much as digits as its factorization.

21274134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557 (or 281 counting only the distinct ones).

The product of its digits is 1344, while the sum is 24.

The square root of 21274134 is about 4612.3891856607. The cubic root of 21274134 is about 277.0877312937.

Multiplying 21274134 by its sum of digits (24), we get a square (510579216 = 22596²).

The spelling of 21274134 in words is "twenty-one million, two hundred seventy-four thousand, one hundred thirty-four".