21260081736 has 48 divisors (see below), whose sum is σ = 57587861760. Its totient is φ = 7085651040.

The previous prime is 21260081719. The next prime is 21260081789. The reversal of 21260081736 is 63718006212.

21260081736 is a `hidden beast` number, since 2 + 1 + 2 + 600 + 8 + 17 + 36 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21260081736.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 589521 + ... + 624543.

It is an arithmetic number, because the mean of its divisors is an integer number (1199747120).

Almost surely, 2^21260081736 is an apocalyptic number.

It is an amenable number.

21260081736 is an abundant number, since it is smaller than the sum of its proper divisors (36327780024).

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

21260081736 is a wasteful number, since it uses less digits than its factorization.

21260081736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43466 (or 43459 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

Adding to 21260081736 its reverse (63718006212), we get a palindrome (84978087948).

The spelling of 21260081736 in words is "twenty-one billion, two hundred sixty million, eighty-one thousand, seven hundred thirty-six".