81469729619 has 4 divisors (see below), whose sum is σ = 81883281744. Its totient is φ = 81056177496.

The previous prime is 81469729613. The next prime is 81469729681. The reversal of 81469729619 is 91692796418.

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 81469729619 - 2²⁴ = 81452952403 is a prime.

It is a super-2 number, since 2×81469729619² (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 (81469729613) 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, 206775767 + ... + 206776160.

It is an arithmetic number, because the mean of its divisors is an integer number (20470820436).

Almost surely, 2^81469729619 is an apocalyptic number.

81469729619 is a deficient number, since it is larger than the sum of its proper divisors (413552125).

81469729619 is a wasteful number, since it uses less digits than its factorization.

81469729619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413552124.

The product of its digits is 11757312, while the sum is 62.

The spelling of 81469729619 in words is "eighty-one billion, four hundred sixty-nine million, seven hundred twenty-nine thousand, six hundred nineteen".