81829815772 has 6 divisors (see below), whose sum is σ = 143202177608. Its totient is φ = 40914907884.

The previous prime is 81829815737. The next prime is 81829815797. The reversal of 81829815772 is 27751892818.

It is a super-2 number, since 2×81829815772² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10228726968 + ... + 10228726975.

Almost surely, 2^81829815772 is an apocalyptic number.

It is an amenable number.

81829815772 is a deficient number, since it is larger than the sum of its proper divisors (61372361836).

81829815772 is a wasteful number, since it uses less digits than its factorization.

81829815772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20457453947 (or 20457453945 counting only the distinct ones).

The product of its digits is 4515840, while the sum is 58.

The spelling of 81829815772 in words is "eighty-one billion, eight hundred twenty-nine million, eight hundred fifteen thousand, seven hundred seventy-two".