81491466 has 32 divisors (see below), whose sum is σ = 186738048. Its totient is φ = 23224320.

The previous prime is 81491447. The next prime is 81491471. The reversal of 81491466 is 66419418.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15946 + ... + 20426.

It is an arithmetic number, because the mean of its divisors is an integer number (5835564).

Almost surely, 2^81491466 is an apocalyptic number.

81491466 is an abundant number, since it is smaller than the sum of its proper divisors (105246582).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81491466 is a wasteful number, since it uses less digits than its factorization.

81491466 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4926.

The product of its digits is 41472, while the sum is 39.

The square root of 81491466 is about 9027.2623757150. The cubic root of 81491466 is about 433.5481894415.

The spelling of 81491466 in words is "eighty-one million, four hundred ninety-one thousand, four hundred sixty-six".