81651519586 has 16 divisors (see below), whose sum is σ = 150741267264. Its totient is φ = 32301699984.

The previous prime is 81651519559. The next prime is 81651519611. The reversal of 81651519586 is 68591515618.

It is a super-2 number, since 2×81651519586² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 224317180 + ... + 224317543.

It is an arithmetic number, because the mean of its divisors is an integer number (9421329204).

Almost surely, 2^81651519586 is an apocalyptic number.

81651519586 is a deficient number, since it is larger than the sum of its proper divisors (69089747678).

81651519586 is a wasteful number, since it uses less digits than its factorization.

81651519586 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448634745.

The product of its digits is 2592000, while the sum is 55.

The spelling of 81651519586 in words is "eighty-one billion, six hundred fifty-one million, five hundred nineteen thousand, five hundred eighty-six".