81507349 has 16 divisors (see below), whose sum is σ = 101831040. Its totient is φ = 63380160.

The previous prime is 81507329. The next prime is 81507383. The reversal of 81507349 is 94370518.

It is a cyclic number.

It is not a de Polignac number, because 81507349 - 2⁹ = 81506837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81507319) 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, 53847 + ... + 55339.

It is an arithmetic number, because the mean of its divisors is an integer number (6364440).

Almost surely, 2^81507349 is an apocalyptic number.

It is an amenable number.

81507349 is a deficient number, since it is larger than the sum of its proper divisors (20323691).

81507349 is a wasteful number, since it uses less digits than its factorization.

81507349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2220.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 81507349 is about 9028.1420569240. The cubic root of 81507349 is about 433.5763543481.

The spelling of 81507349 in words is "eighty-one million, five hundred seven thousand, three hundred forty-nine".