21447142 has 16 divisors (see below), whose sum is σ = 32649120. Its totient is φ = 10565568.

The previous prime is 21447137. The next prime is 21447203. The reversal of 21447142 is 24174412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52234 + ... + 52642.

It is an arithmetic number, because the mean of its divisors is an integer number (2040570).

Almost surely, 2^21447142 is an apocalyptic number.

21447142 is a deficient number, since it is larger than the sum of its proper divisors (11201978).

21447142 is a wasteful number, since it uses less digits than its factorization.

21447142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735.

The product of its digits is 1792, while the sum is 25.

The square root of 21447142 is about 4631.1059154375. The cubic root of 21447142 is about 277.8368260722.

The spelling of 21447142 in words is "twenty-one million, four hundred forty-seven thousand, one hundred forty-two".