21131336707 has 16 divisors (see below), whose sum is σ = 23554440000. Its totient is φ = 18822916224.

The previous prime is 21131336671. The next prime is 21131336729. The reversal of 21131336707 is 70763313112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21131336707 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21131336747) 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, 720394 + ... + 749152.

It is an arithmetic number, because the mean of its divisors is an integer number (1472152500).

Almost surely, 2^21131336707 is an apocalyptic number.

21131336707 is a deficient number, since it is larger than the sum of its proper divisors (2423103293).

21131336707 is a wasteful number, since it uses less digits than its factorization.

21131336707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30750.

The product of its (nonzero) digits is 15876, while the sum is 34.

Adding to 21131336707 its reverse (70763313112), we get a palindrome (91894649819).

The spelling of 21131336707 in words is "twenty-one billion, one hundred thirty-one million, three hundred thirty-six thousand, seven hundred seven".