81413777 has 16 divisors (see below), whose sum is σ = 85396032. Its totient is φ = 77563200.

The previous prime is 81413747. The next prime is 81413789. The reversal of 81413777 is 77731418.

It is a cyclic number.

It is not a de Polignac number, because 81413777 - 2¹⁸ = 81151633 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81413777.

It is not an unprimeable number, because it can be changed into a prime (81413737) 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, 358538 + ... + 358764.

It is an arithmetic number, because the mean of its divisors is an integer number (5337252).

Almost surely, 2^81413777 is an apocalyptic number.

It is an amenable number.

81413777 is a deficient number, since it is larger than the sum of its proper divisors (3982255).

81413777 is a wasteful number, since it uses less digits than its factorization.

81413777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 448.

The product of its digits is 32928, while the sum is 38.

The square root of 81413777 is about 9022.9583286193. The cubic root of 81413777 is about 433.4103728249.

The spelling of 81413777 in words is "eighty-one million, four hundred thirteen thousand, seven hundred seventy-seven".