81677077619 has 4 divisors (see below), whose sum is σ = 81678276744. Its totient is φ = 81675878496.

The previous prime is 81677077543. The next prime is 81677077627. The reversal of 81677077619 is 91677077618.

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 81677077619 - 2¹² = 81677073523 is a prime.

It is a super-2 number, since 2×81677077619² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81677077639) 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, 490817 + ... + 635810.

It is an arithmetic number, because the mean of its divisors is an integer number (20419569186).

Almost surely, 2^81677077619 is an apocalyptic number.

81677077619 is a deficient number, since it is larger than the sum of its proper divisors (1199125).

81677077619 is a wasteful number, since it uses less digits than its factorization.

81677077619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1199124.

The product of its (nonzero) digits is 6223392, while the sum is 59.

Subtracting 81677077619 from its reverse (91677077618), we obtain a palindrome (9999999999).

The spelling of 81677077619 in words is "eighty-one billion, six hundred seventy-seven million, seventy-seven thousand, six hundred nineteen".