81807377 has 4 divisors (see below), whose sum is σ = 82928100. Its totient is φ = 80686656.

The previous prime is 81807317. The next prime is 81807379. The reversal of 81807377 is 77370818.

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 14714896 + 67092481 = 3836^2 + 8191^2 .

It is a cyclic number.

It is not a de Polignac number, because 81807377 - 2¹⁴ = 81790993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81807379) 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, 560252 + ... + 560397.

It is an arithmetic number, because the mean of its divisors is an integer number (20732025).

Almost surely, 2^81807377 is an apocalyptic number.

It is an amenable number.

81807377 is a deficient number, since it is larger than the sum of its proper divisors (1120723).

81807377 is a wasteful number, since it uses less digits than its factorization.

81807377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1120722.

The product of its (nonzero) digits is 65856, while the sum is 41.

The square root of 81807377 is about 9044.7430588160. The cubic root of 81807377 is about 434.1077001289.

The spelling of 81807377 in words is "eighty-one million, eight hundred seven thousand, three hundred seventy-seven".