21710142 has 24 divisors (see below), whose sum is σ = 47414016. Its totient is φ = 7178976.

The previous prime is 21710131. The next prime is 21710149. The reversal of 21710142 is 24101712.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21710149) 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 11 ways as a sum of consecutive naturals, for example, 2463 + ... + 7034.

It is an arithmetic number, because the mean of its divisors is an integer number (1975584).

Almost surely, 2^21710142 is an apocalyptic number.

21710142 is an abundant number, since it is smaller than the sum of its proper divisors (25703874).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21710142 is a wasteful number, since it uses less digits than its factorization.

21710142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9632 (or 9629 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 18.

The square root of 21710142 is about 4659.4143408802. The cubic root of 21710142 is about 278.9678924011.

Adding to 21710142 its reverse (24101712), we get a palindrome (45811854).

The spelling of 21710142 in words is "twenty-one million, seven hundred ten thousand, one hundred forty-two".