21131336740 has 48 divisors (see below), whose sum is σ = 44879934960. Its totient is φ = 8356884480.

The previous prime is 21131336729. The next prime is 21131336741. The reversal of 21131336740 is 4763313112.

It can be written as a sum of positive squares in 8 ways, for example, as 270734116 + 20860602624 = 16454^2 + 144432^2 .

It is not an unprimeable number, because it can be changed into a prime (21131336741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 912910 + ... + 935770.

It is an arithmetic number, because the mean of its divisors is an integer number (934998645).

Almost surely, 2^21131336740 is an apocalyptic number.

21131336740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21131336740 is an abundant number, since it is smaller than the sum of its proper divisors (23748598220).

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

21131336740 is a wasteful number, since it uses less digits than its factorization.

21131336740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23392 (or 23390 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 31.

Adding to 21131336740 its reverse (4763313112), we get a palindrome (25894649852).

The spelling of 21131336740 in words is "twenty-one billion, one hundred thirty-one million, three hundred thirty-six thousand, seven hundred forty".