21111142 has 12 divisors (see below), whose sum is σ = 34290540. Its totient is φ = 9743448.

The previous prime is 21111113. The next prime is 21111143. The reversal of 21111142 is 24111112.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111143) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 30892 + ... + 31567.

It is an arithmetic number, because the mean of its divisors is an integer number (2857545).

Almost surely, 2^21111142 is an apocalyptic number.

21111142 is a deficient number, since it is larger than the sum of its proper divisors (13179398).

21111142 is a wasteful number, since it uses less digits than its factorization.

21111142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62487 (or 62474 counting only the distinct ones).

The product of its digits is 16, while the sum is 13.

The square root of 21111142 is about 4594.6862787355. The cubic root of 21111142 is about 276.3782795232.

Adding to 21111142 its reverse (24111112), we get a palindrome (45222254).

The spelling of 21111142 in words is "twenty-one million, one hundred eleven thousand, one hundred forty-two".