21361242140 has 48 divisors (see below), whose sum is σ = 51430878912. Its totient is φ = 7300440576.

The previous prime is 21361242131. The next prime is 21361242151. The reversal of 21361242140 is 4124216312.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199919 + ... + 287558.

It is an arithmetic number, because the mean of its divisors is an integer number (1071476644).

Almost surely, 2^21361242140 is an apocalyptic number.

21361242140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21361242140 is an abundant number, since it is smaller than the sum of its proper divisors (30069636772).

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

21361242140 is a wasteful number, since it uses less digits than its factorization.

21361242140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487806 (or 487804 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

Adding to 21361242140 its reverse (4124216312), we get a palindrome (25485458452).

The spelling of 21361242140 in words is "twenty-one billion, three hundred sixty-one million, two hundred forty-two thousand, one hundred forty".