81816653515 has 16 divisors (see below), whose sum is σ = 104128174656. Its totient is φ = 61581168000.

The previous prime is 81816653507. The next prime is 81816653531. The reversal of 81816653515 is 51535661818.

It is not a de Polignac number, because 81816653515 - 2³ = 81816653507 is a prime.

It is a super-3 number, since 3×81816653515³ (a number of 34 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5824536 + ... + 5838565.

It is an arithmetic number, because the mean of its divisors is an integer number (6508010916).

Almost surely, 2^81816653515 is an apocalyptic number.

81816653515 is a deficient number, since it is larger than the sum of its proper divisors (22311521141).

81816653515 is a wasteful number, since it uses less digits than its factorization.

81816653515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11663190.

The product of its digits is 864000, while the sum is 49.

The spelling of 81816653515 in words is "eighty-one billion, eight hundred sixteen million, six hundred fifty-three thousand, five hundred fifteen".