21442012 has 6 divisors (see below), whose sum is σ = 37523528. Its totient is φ = 10721004.

The previous prime is 21442009. The next prime is 21442019. The reversal of 21442012 is 21024412.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2680248 + ... + 2680255.

Almost surely, 2^21442012 is an apocalyptic number.

It is an amenable number.

21442012 is a deficient number, since it is larger than the sum of its proper divisors (16081516).

21442012 is a wasteful number, since it uses less digits than its factorization.

21442012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5360507 (or 5360505 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21442012 is about 4630.5520189282. The cubic root of 21442012 is about 277.8146721247.

Adding to 21442012 its reverse (21024412), we get a palindrome (42466424).

The spelling of 21442012 in words is "twenty-one million, four hundred forty-two thousand, twelve".