81790186683631 has 4 divisors (see below), whose sum is σ = 81886072014712. Its totient is φ = 81694301352552.

The previous prime is 81790186683563. The next prime is 81790186683661. The reversal of 81790186683631 is 13638668109718.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81790186683631 - 2³¹ = 81788039199983 is a prime.

It is a super-2 number, since 2×81790186683631² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81790186683661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47942664261 + ... + 47942665966.

It is an arithmetic number, because the mean of its divisors is an integer number (20471518003678).

Almost surely, 2^{81790186683631} is an apocalyptic number.

81790186683631 is a deficient number, since it is larger than the sum of its proper divisors (95885331081).

81790186683631 is an equidigital number, since it uses as much as digits as its factorization.

81790186683631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95885331080.

The product of its (nonzero) digits is 62705664, while the sum is 67.

The spelling of 81790186683631 in words is "eighty-one trillion, seven hundred ninety billion, one hundred eighty-six million, six hundred eighty-three thousand, six hundred thirty-one".