81205977683 has 8 divisors (see below), whose sum is σ = 84018088080. Its totient is φ = 78394660960.

The previous prime is 81205977649. The next prime is 81205977691. The reversal of 81205977683 is 38677950218.

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 81205977683 - 2¹⁴ = 81205961299 is a prime.

It is a super-2 number, since 2×81205977683² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81205973683) 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, 13613 + ... + 403233.

It is an arithmetic number, because the mean of its divisors is an integer number (10502261010).

Almost surely, 2^81205977683 is an apocalyptic number.

81205977683 is a deficient number, since it is larger than the sum of its proper divisors (2812110397).

81205977683 is a wasteful number, since it uses less digits than its factorization.

81205977683 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396837.

The product of its (nonzero) digits is 5080320, while the sum is 56.

The spelling of 81205977683 in words is "eighty-one billion, two hundred five million, nine hundred seventy-seven thousand, six hundred eighty-three".