21798142 has 8 divisors (see below), whose sum is σ = 33494832. Its totient is φ = 10633200.

The previous prime is 21798137. The next prime is 21798157. The reversal of 21798142 is 24189712.

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

It is a junction number, because it is equal to n+sod(n) for n = 21798098 and 21798107.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132834 + ... + 132997.

It is an arithmetic number, because the mean of its divisors is an integer number (4186854).

Almost surely, 2^21798142 is an apocalyptic number.

21798142 is a deficient number, since it is larger than the sum of its proper divisors (11696690).

21798142 is a wasteful number, since it uses less digits than its factorization.

21798142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265874.

The product of its digits is 8064, while the sum is 34.

The square root of 21798142 is about 4668.8480377926. The cubic root of 21798142 is about 279.3443075618.

The spelling of 21798142 in words is "twenty-one million, seven hundred ninety-eight thousand, one hundred forty-two".