81840146 has 8 divisors (see below), whose sum is σ = 126993420. Its totient is φ = 39509008.

The previous prime is 81840133. The next prime is 81840149. The reversal of 81840146 is 64104818.

It can be written as a sum of positive squares in 2 ways, for example, as 76755121 + 5085025 = 8761^2 + 2255^2 .

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

It is not an unprimeable number, because it can be changed into a prime (81840149) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 705461 + ... + 705576.

Almost surely, 2^81840146 is an apocalyptic number.

81840146 is a deficient number, since it is larger than the sum of its proper divisors (45153274).

81840146 is a wasteful number, since it uses less digits than its factorization.

81840146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1411068.

The product of its (nonzero) digits is 6144, while the sum is 32.

The square root of 81840146 is about 9046.5543716931. The cubic root of 81840146 is about 434.1656548709.

The spelling of 81840146 in words is "eighty-one million, eight hundred forty thousand, one hundred forty-six".