21442772 has 24 divisors (see below), whose sum is σ = 40543776. Its totient is φ = 9864288.

The previous prime is 21442753. The next prime is 21442777. The reversal of 21442772 is 27724412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442777) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23843 + ... + 24725.

It is an arithmetic number, because the mean of its divisors is an integer number (1689324).

Almost surely, 2^21442772 is an apocalyptic number.

It is an amenable number.

21442772 is a deficient number, since it is larger than the sum of its proper divisors (19101004).

21442772 is a wasteful number, since it uses less digits than its factorization.

21442772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1367 (or 1365 counting only the distinct ones).

The product of its digits is 6272, while the sum is 29.

The square root of 21442772 is about 4630.6340818510. The cubic root of 21442772 is about 277.8179544139.

The spelling of 21442772 in words is "twenty-one million, four hundred forty-two thousand, seven hundred seventy-two".