21081726337 has 8 divisors (see below), whose sum is σ = 24585104000. Its totient is φ = 18070050852.

The previous prime is 21081726311. The next prime is 21081726371. The reversal of 21081726337 is 73362718012.

It is a happy number.

It is not a de Polignac number, because 21081726337 - 2²³ = 21073337729 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21081726337.

It is not an unprimeable number, because it can be changed into a prime (21081720337) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30731037 + ... + 30731722.

It is an arithmetic number, because the mean of its divisors is an integer number (3073138000).

Almost surely, 2^21081726337 is an apocalyptic number.

It is an amenable number.

21081726337 is a deficient number, since it is larger than the sum of its proper divisors (3503377663).

21081726337 is an frugal number, since it uses more digits than its factorization.

21081726337 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61462780 (or 61462766 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 40.

The spelling of 21081726337 in words is "twenty-one billion, eighty-one million, seven hundred twenty-six thousand, three hundred thirty-seven".