21102142 has 4 divisors (see below), whose sum is σ = 31653216. Its totient is φ = 10551070.

The previous prime is 21102113. The next prime is 21102161. The reversal of 21102142 is 24120112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5275534 + ... + 5275537.

It is an arithmetic number, because the mean of its divisors is an integer number (7913304).

Almost surely, 2^21102142 is an apocalyptic number.

21102142 is a deficient number, since it is larger than the sum of its proper divisors (10551074).

21102142 is a wasteful number, since it uses less digits than its factorization.

21102142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10551073.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21102142 is about 4593.7067821096. The cubic root of 21102142 is about 276.3389991901.

Adding to 21102142 its reverse (24120112), we get a palindrome (45222254).

The spelling of 21102142 in words is "twenty-one million, one hundred two thousand, one hundred forty-two".