81629993517 has 16 divisors (see below), whose sum is σ = 112015050240. Its totient is φ = 52838609472.

The previous prime is 81629993483. The next prime is 81629993537. The reversal of 81629993517 is 71539992618.

It is not a de Polignac number, because 81629993517 - 2¹⁴ = 81629977133 is a prime.

It is a super-3 number, since 3×81629993517³ (a number of 34 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81629993537) 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, 714478 + ... + 820815.

It is an arithmetic number, because the mean of its divisors is an integer number (7000940640).

Almost surely, 2^81629993517 is an apocalyptic number.

It is an amenable number.

81629993517 is a deficient number, since it is larger than the sum of its proper divisors (30385056723).

81629993517 is a wasteful number, since it uses less digits than its factorization.

81629993517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1535812.

The product of its digits is 7348320, while the sum is 60.

The spelling of 81629993517 in words is "eighty-one billion, six hundred twenty-nine million, nine hundred ninety-three thousand, five hundred seventeen".