81000515 has 16 divisors (see below), whose sum is σ = 102539520. Its totient is φ = 61256160.

The previous prime is 81000487. The next prime is 81000523. The reversal of 81000515 is 51500018.

It is not a de Polignac number, because 81000515 - 2¹⁴ = 80984131 is a prime.

It is a super-2 number, since 2×81000515² = 13122166860530450, which contains 22 as substring.

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, 78050 + ... + 79080.

It is an arithmetic number, because the mean of its divisors is an integer number (6408720).

Almost surely, 2^81000515 is an apocalyptic number.

81000515 is a deficient number, since it is larger than the sum of its proper divisors (21539005).

81000515 is a wasteful number, since it uses less digits than its factorization.

81000515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1882.

The product of its (nonzero) digits is 200, while the sum is 20.

The square root of 81000515 is about 9000.0286110656. The cubic root of 81000515 is about 432.6757880761.

The spelling of 81000515 in words is "eighty-one million, five hundred fifteen", and thus it is an aban number.