21331142 has 8 divisors (see below), whose sum is σ = 36567696. Its totient is φ = 9141912.

The previous prime is 21331133. The next prime is 21331147. The reversal of 21331142 is 24113312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21331142.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331147) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 761813 + ... + 761840.

It is an arithmetic number, because the mean of its divisors is an integer number (4570962).

Almost surely, 2^21331142 is an apocalyptic number.

21331142 is a deficient number, since it is larger than the sum of its proper divisors (15236554).

21331142 is a wasteful number, since it uses less digits than its factorization.

21331142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1523662.

The product of its digits is 144, while the sum is 17.

The square root of 21331142 is about 4618.5649286331. The cubic root of 21331142 is about 277.3350132546.

Adding to 21331142 its reverse (24113312), we get a palindrome (45444454).

The spelling of 21331142 in words is "twenty-one million, three hundred thirty-one thousand, one hundred forty-two".