81349373787 has 8 divisors (see below), whose sum is σ = 118326361920. Its totient is φ = 49302650760.

The previous prime is 81349373783. The next prime is 81349373797. The reversal of 81349373787 is 78737394318.

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

It is not a de Polignac number, because 81349373787 - 2² = 81349373783 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81349373787.

It is not an unprimeable number, because it can be changed into a prime (81349373783) 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, 1232566237 + ... + 1232566302.

It is an arithmetic number, because the mean of its divisors is an integer number (14790795240).

Almost surely, 2^81349373787 is an apocalyptic number.

81349373787 is a deficient number, since it is larger than the sum of its proper divisors (36976988133).

81349373787 is a wasteful number, since it uses less digits than its factorization.

81349373787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2465132553.

The product of its digits is 21337344, while the sum is 60.

The spelling of 81349373787 in words is "eighty-one billion, three hundred forty-nine million, three hundred seventy-three thousand, seven hundred eighty-seven".