81646103577 has 4 divisors (see below), whose sum is σ = 108861471440. Its totient is φ = 54430735716.

The previous prime is 81646103557. The next prime is 81646103597. The reversal of 81646103577 is 77530164618.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (81646103557) and next prime (81646103597).

It is not a de Polignac number, because 81646103577 - 2¹¹ = 81646101529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81646103527) 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, 13607683927 + ... + 13607683932.

It is an arithmetic number, because the mean of its divisors is an integer number (27215367860).

Almost surely, 2^81646103577 is an apocalyptic number.

It is an amenable number.

81646103577 is a deficient number, since it is larger than the sum of its proper divisors (27215367863).

81646103577 is a wasteful number, since it uses less digits than its factorization.

81646103577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27215367862.

The product of its (nonzero) digits is 846720, while the sum is 48.

The spelling of 81646103577 in words is "eighty-one billion, six hundred forty-six million, one hundred three thousand, five hundred seventy-seven".