81799494 has 16 divisors (see below), whose sum is σ = 186970368. Its totient is φ = 23371272.

The previous prime is 81799463. The next prime is 81799499. The reversal of 81799494 is 49499718.

It is a super-3 number, since 3×81799494³ (a number of 25 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81799499) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 973762 + ... + 973845.

It is an arithmetic number, because the mean of its divisors is an integer number (11685648).

Almost surely, 2^81799494 is an apocalyptic number.

81799494 is an abundant number, since it is smaller than the sum of its proper divisors (105170874).

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

81799494 is a wasteful number, since it uses less digits than its factorization.

81799494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1947619.

The product of its digits is 653184, while the sum is 51.

The square root of 81799494 is about 9044.3072703220. The cubic root of 81799494 is about 434.0937560689.

The spelling of 81799494 in words is "eighty-one million, seven hundred ninety-nine thousand, four hundred ninety-four".