81787150765 has 16 divisors (see below), whose sum is σ = 99077888448. Its totient is φ = 64807714816.

The previous prime is 81787150763. The next prime is 81787150793. The reversal of 81787150765 is 56705178718.

It is a cyclic number.

It is not a de Polignac number, because 81787150765 - 2¹ = 81787150763 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81787150763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6136749 + ... + 6150061.

It is an arithmetic number, because the mean of its divisors is an integer number (6192368028).

Almost surely, 2^81787150765 is an apocalyptic number.

It is an amenable number.

81787150765 is a deficient number, since it is larger than the sum of its proper divisors (17290737683).

81787150765 is a wasteful number, since it uses less digits than its factorization.

81787150765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24908.

The product of its (nonzero) digits is 3292800, while the sum is 55.

The spelling of 81787150765 in words is "eighty-one billion, seven hundred eighty-seven million, one hundred fifty thousand, seven hundred sixty-five".