21704274 has 96 divisors (see below), whose sum is σ = 53778816. Its totient is φ = 6531840.

The previous prime is 21704261. The next prime is 21704279. The reversal of 21704274 is 47240712.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21704279) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 305659 + ... + 305729.

It is an arithmetic number, because the mean of its divisors is an integer number (560196).

Almost surely, 2^21704274 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21704274, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26889408).

21704274 is an abundant number, since it is smaller than the sum of its proper divisors (32074542).

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

21704274 is a wasteful number, since it uses less digits than its factorization.

21704274 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 27.

The square root of 21704274 is about 4658.7846054524. The cubic root of 21704274 is about 278.9427562059.

Adding to 21704274 its reverse (47240712), we get a palindrome (68944986).

The spelling of 21704274 in words is "twenty-one million, seven hundred four thousand, two hundred seventy-four".