21202140 has 48 divisors (see below), whose sum is σ = 61286400. Its totient is φ = 5471040.

The previous prime is 21202133. The next prime is 21202141. The reversal of 21202140 is 4120212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3840 + ... + 7559.

It is an arithmetic number, because the mean of its divisors is an integer number (1276800).

Almost surely, 2^21202140 is an apocalyptic number.

21202140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21202140 is an abundant number, since it is smaller than the sum of its proper divisors (40084260).

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

21202140 is a wasteful number, since it uses less digits than its factorization.

21202140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11442 (or 11440 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 21202140 is about 4604.5781565742. The cubic root of 21202140 is about 276.7748129654.

Adding to 21202140 its reverse (4120212), we get a palindrome (25322352).

The spelling of 21202140 in words is "twenty-one million, two hundred two thousand, one hundred forty".