81842474 has 8 divisors (see below), whose sum is σ = 140301408. Its totient is φ = 35075340.

The previous prime is 81842429. The next prime is 81842479. The reversal of 81842474 is 47424818.

It is a happy number.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (81842479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2922932 + ... + 2922959.

It is an arithmetic number, because the mean of its divisors is an integer number (17537676).

Almost surely, 2^81842474 is an apocalyptic number.

81842474 is a deficient number, since it is larger than the sum of its proper divisors (58458934).

81842474 is a wasteful number, since it uses less digits than its factorization.

81842474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5845900.

The product of its digits is 57344, while the sum is 38.

The square root of 81842474 is about 9046.6830385506. The cubic root of 81842474 is about 434.1697715467.

Adding to 81842474 its product of digits (57344), we get a palindrome (81899818).

The spelling of 81842474 in words is "eighty-one million, eight hundred forty-two thousand, four hundred seventy-four".