81737500993 has 8 divisors (see below), whose sum is σ = 88232385600. Its totient is φ = 75487706448.

The previous prime is 81737500991. The next prime is 81737500997. The reversal of 81737500993 is 39900573718.

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 81737500993 - 2¹ = 81737500991 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 81737500993.

It is not an unprimeable number, because it can be changed into a prime (81737500991) 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, 61271823 + ... + 61273156.

It is an arithmetic number, because the mean of its divisors is an integer number (11029048200).

Almost surely, 2^81737500993 is an apocalyptic number.

It is an amenable number.

81737500993 is a deficient number, since it is larger than the sum of its proper divisors (6494884607).

81737500993 is a wasteful number, since it uses less digits than its factorization.

81737500993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122545031.

The product of its (nonzero) digits is 1428840, while the sum is 52.

The spelling of 81737500993 in words is "eighty-one billion, seven hundred thirty-seven million, five hundred thousand, nine hundred ninety-three".