21081727373 has 8 divisors (see below), whose sum is σ = 24547995648. Its totient is φ = 17729107344.

The previous prime is 21081727369. The next prime is 21081727391. The reversal of 21081727373 is 37372718012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21081727373 - 2² = 21081727369 is a prime.

It is a super-2 number, since 2×21081727373² (a number of 21 digits) contains 22 as substring.

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 21081727373.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21081727313) 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, 28411661 + ... + 28412402.

It is an arithmetic number, because the mean of its divisors is an integer number (3068499456).

Almost surely, 2^21081727373 is an apocalyptic number.

It is an amenable number.

21081727373 is a deficient number, since it is larger than the sum of its proper divisors (3466268275).

21081727373 is an equidigital number, since it uses as much as digits as its factorization.

21081727373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56824123.

The product of its (nonzero) digits is 98784, while the sum is 41.

The spelling of 21081727373 in words is "twenty-one billion, eighty-one million, seven hundred twenty-seven thousand, three hundred seventy-three".