21704046 has 64 divisors (see below), whose sum is σ = 54018048. Its totient is φ = 5660928.

The previous prime is 21704029. The next prime is 21704069. The reversal of 21704046 is 64040712.

It is a super-2 number, since 2×21704046² = 942131225540232, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69186 + ... + 69498.

It is an arithmetic number, because the mean of its divisors is an integer number (844032).

Almost surely, 2^21704046 is an apocalyptic number.

21704046 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21704046, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27009024).

21704046 is an abundant number, since it is smaller than the sum of its proper divisors (32314002).

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

21704046 is a wasteful number, since it uses less digits than its factorization.

21704046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 465.

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

The square root of 21704046 is about 4658.7601354867. The cubic root of 21704046 is about 278.9417794525.

Adding to 21704046 its reverse (64040712), we get a palindrome (85744758).

It can be divided in two parts, 2170 and 4046, that added together give a triangular number (6216 = T₁₁₁).

The spelling of 21704046 in words is "twenty-one million, seven hundred four thousand, forty-six".