81607849 has 4 divisors (see below), whose sum is σ = 81671040. Its totient is φ = 81544660.

The previous prime is 81607847. The next prime is 81607853. The reversal of 81607849 is 94870618.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81607849 - 2¹ = 81607847 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81607843) 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, 29617 + ... + 32254.

It is an arithmetic number, because the mean of its divisors is an integer number (20417760).

Almost surely, 2^81607849 is an apocalyptic number.

It is an amenable number.

81607849 is a deficient number, since it is larger than the sum of its proper divisors (63191).

81607849 is a wasteful number, since it uses less digits than its factorization.

81607849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63190.

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 81607849 is about 9033.7062715145. The cubic root of 81607849 is about 433.7544835886.

The spelling of 81607849 in words is "eighty-one million, six hundred seven thousand, eight hundred forty-nine".