81515273 has 12 divisors (see below), whose sum is σ = 94993920. Its totient is φ = 69745032.

The previous prime is 81515267. The next prime is 81515293. The reversal of 81515273 is 37251518.

It is not a de Polignac number, because 81515273 - 2⁶ = 81515209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81515233) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35288 + ... + 37526.

It is an arithmetic number, because the mean of its divisors is an integer number (7916160).

Almost surely, 2^81515273 is an apocalyptic number.

It is an amenable number.

81515273 is a deficient number, since it is larger than the sum of its proper divisors (13478647).

81515273 is a wasteful number, since it uses less digits than its factorization.

81515273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2996 (or 2989 counting only the distinct ones).

The product of its digits is 8400, while the sum is 32.

The square root of 81515273 is about 9028.5808962428. The cubic root of 81515273 is about 433.5904044010.

The spelling of 81515273 in words is "eighty-one million, five hundred fifteen thousand, two hundred seventy-three".