81187474 has 8 divisors (see below), whose sum is σ = 121820220. Its totient is φ = 40580736.

The previous prime is 81187459. The next prime is 81187489. The reversal of 81187474 is 47478118.

It is an interprime number because it is at equal distance from previous prime (81187459) and next prime (81187489).

It can be written as a sum of positive squares in 2 ways, for example, as 52490025 + 28697449 = 7245^2 + 5357^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6522 + ... + 14314.

Almost surely, 2^81187474 is an apocalyptic number.

81187474 is a deficient number, since it is larger than the sum of its proper divisors (40632746).

81187474 is a wasteful number, since it uses less digits than its factorization.

81187474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13004.

The product of its digits is 50176, while the sum is 40.

The square root of 81187474 is about 9010.4092026944. The cubic root of 81187474 is about 433.0084216636.

The spelling of 81187474 in words is "eighty-one million, one hundred eighty-seven thousand, four hundred seventy-four".