81749494 has 8 divisors (see below), whose sum is σ = 122910048. Its totient is φ = 40779480.

The previous prime is 81749491. The next prime is 81749513. The reversal of 81749494 is 49494718.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81749491) 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, 46557 + ... + 48280.

It is an arithmetic number, because the mean of its divisors is an integer number (15363756).

Almost surely, 2^81749494 is an apocalyptic number.

81749494 is a deficient number, since it is larger than the sum of its proper divisors (41160554).

81749494 is a wasteful number, since it uses less digits than its factorization.

81749494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95270.

The product of its digits is 290304, while the sum is 46.

The square root of 81749494 is about 9041.5426781053. The cubic root of 81749494 is about 434.0052913340.

The spelling of 81749494 in words is "eighty-one million, seven hundred forty-nine thousand, four hundred ninety-four".