81374505 has 8 divisors (see below), whose sum is σ = 130199232. Its totient is φ = 43399728.

The previous prime is 81374477. The next prime is 81374519. The reversal of 81374505 is 50547318.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81374505 - 2⁶ = 81374441 is a prime.

It is a Curzon number.

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, 2712469 + ... + 2712498.

It is an arithmetic number, because the mean of its divisors is an integer number (16274904).

Almost surely, 2^81374505 is an apocalyptic number.

It is an amenable number.

81374505 is a deficient number, since it is larger than the sum of its proper divisors (48824727).

81374505 is a wasteful number, since it uses less digits than its factorization.

81374505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5424975.

The product of its (nonzero) digits is 16800, while the sum is 33.

The square root of 81374505 is about 9020.7818397299. The cubic root of 81374505 is about 433.3406727882.

The spelling of 81374505 in words is "eighty-one million, three hundred seventy-four thousand, five hundred five".