21000142 has 8 divisors (see below), whose sum is σ = 31554432. Its totient is φ = 10482000.

The previous prime is 21000139. The next prime is 21000143. The reversal of 21000142 is 24100012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000143) 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, 7534 + ... + 9937.

It is an arithmetic number, because the mean of its divisors is an integer number (3944304).

Almost surely, 2^21000142 is an apocalyptic number.

21000142 is a deficient number, since it is larger than the sum of its proper divisors (10554290).

21000142 is a wasteful number, since it uses less digits than its factorization.

21000142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18074.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21000142 is about 4582.5911883999. The cubic root of 21000142 is about 275.8930394895.

Adding to 21000142 its reverse (24100012), we get a palindrome (45100154).

The spelling of 21000142 in words is "twenty-one million, one hundred forty-two", and thus it is an aban number.