86780781 has 8 divisors (see below), whose sum is σ = 128564160. Its totient is φ = 57853836.

The previous prime is 86780777. The next prime is 86780783. The reversal of 86780781 is 18708768.

It is not a de Polignac number, because 86780781 - 2² = 86780777 is a prime.

It is a super-2 number, since 2×86780781² = 15061807901939922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86780783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1607025 + ... + 1607078.

It is an arithmetic number, because the mean of its divisors is an integer number (16070520).

Almost surely, 2^86780781 is an apocalyptic number.

It is an amenable number.

86780781 is a deficient number, since it is larger than the sum of its proper divisors (41783379).

86780781 is a wasteful number, since it uses less digits than its factorization.

86780781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3214112 (or 3214106 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 45.

The square root of 86780781 is about 9315.6202692038. The cubic root of 86780781 is about 442.7322767881.

The spelling of 86780781 in words is "eighty-six million, seven hundred eighty thousand, seven hundred eighty-one".