81593869939 has 8 divisors (see below), whose sum is σ = 82569616272. Its totient is φ = 80623470720.

The previous prime is 81593869897. The next prime is 81593869969. The reversal of 81593869939 is 93996839518.

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 81593869939 - 2²³ = 81585481331 is a prime.

It is a super-2 number, since 2×81593869939² (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 (81593869969) 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, 1306074 + ... + 1367119.

It is an arithmetic number, because the mean of its divisors is an integer number (10321202034).

Almost surely, 2^81593869939 is an apocalyptic number.

81593869939 is a deficient number, since it is larger than the sum of its proper divisors (975746333).

81593869939 is a wasteful number, since it uses less digits than its factorization.

81593869939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2673557.

The product of its digits is 113374080, while the sum is 70.

The spelling of 81593869939 in words is "eighty-one billion, five hundred ninety-three million, eight hundred sixty-nine thousand, nine hundred thirty-nine".