81416513 has 4 divisors (see below), whose sum is σ = 81451860. Its totient is φ = 81381168.

The previous prime is 81416507. The next prime is 81416521. The reversal of 81416513 is 31561418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43864129 + 37552384 = 6623^2 + 6128^2 .

It is a cyclic number.

It is not a de Polignac number, because 81416513 - 2⁶ = 81416449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81416563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13958 + ... + 18911.

It is an arithmetic number, because the mean of its divisors is an integer number (20362965).

Almost surely, 2^81416513 is an apocalyptic number.

It is an amenable number.

81416513 is a deficient number, since it is larger than the sum of its proper divisors (35347).

81416513 is a wasteful number, since it uses less digits than its factorization.

81416513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35346.

The product of its digits is 2880, while the sum is 29.

The square root of 81416513 is about 9023.1099405914. The cubic root of 81416513 is about 433.4152278488.

The spelling of 81416513 in words is "eighty-one million, four hundred sixteen thousand, five hundred thirteen".