21996846 has 64 divisors (see below), whose sum is σ = 51010560. Its totient is φ = 7109208.

The previous prime is 21996841. The next prime is 21996853. The reversal of 21996846 is 64869912.

It is a happy number.

It is a super-2 number, since 2×21996846² = 967722467895432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21996841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 205525 + ... + 205631.

It is an arithmetic number, because the mean of its divisors is an integer number (797040).

Almost surely, 2^21996846 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21996846, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25505280).

21996846 is an abundant number, since it is smaller than the sum of its proper divisors (29013714).

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

21996846 is an equidigital number, since it uses as much as digits as its factorization.

21996846 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 159 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 21996846 is about 4690.0795302425. The cubic root of 21996846 is about 280.1905420740.

It can be divided in two parts, 2199 and 6846, that added together give a triangular number (9045 = T₁₃₄).

The spelling of 21996846 in words is "twenty-one million, nine hundred ninety-six thousand, eight hundred forty-six".