81082749 has 16 divisors (see below), whose sum is σ = 118540800. Its totient is φ = 48890160.

The previous prime is 81082723. The next prime is 81082759. The reversal of 81082749 is 94728018.

It is not a de Polignac number, because 81082749 - 2¹³ = 81074557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81082759) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 394 + ... + 12740.

It is an arithmetic number, because the mean of its divisors is an integer number (7408800).

Almost surely, 2^81082749 is an apocalyptic number.

It is an amenable number.

81082749 is a deficient number, since it is larger than the sum of its proper divisors (37458051).

81082749 is a wasteful number, since it uses less digits than its factorization.

81082749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12560.

The product of its (nonzero) digits is 32256, while the sum is 39.

The square root of 81082749 is about 9004.5959931582. The cubic root of 81082749 is about 432.8221600949.

The spelling of 81082749 in words is "eighty-one million, eighty-two thousand, seven hundred forty-nine".