21442266 has 32 divisors (see below), whose sum is σ = 49190400. Its totient is φ = 6916320.

The previous prime is 21442261. The next prime is 21442273. The reversal of 21442266 is 66224412.

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

It is not an unprimeable number, because it can be changed into a prime (21442261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4731 + ... + 8078.

It is an arithmetic number, because the mean of its divisors is an integer number (1537200).

Almost surely, 2^21442266 is an apocalyptic number.

21442266 is an abundant number, since it is smaller than the sum of its proper divisors (27748134).

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

21442266 is a wasteful number, since it uses less digits than its factorization.

21442266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12851 (or 12845 counting only the distinct ones).

The product of its digits is 4608, while the sum is 27.

The square root of 21442266 is about 4630.5794453826. The cubic root of 21442266 is about 277.8157691089.

Adding to 21442266 its reverse (66224412), we get a palindrome (87666678).

The spelling of 21442266 in words is "twenty-one million, four hundred forty-two thousand, two hundred sixty-six".