81007277 has 12 divisors (see below), whose sum is σ = 88334100. Its totient is φ = 74251008.

The previous prime is 81007271. The next prime is 81007291. The reversal of 81007277 is 77270018.

It can be written as a sum of positive squares in 6 ways, for example, as 10883401 + 70123876 = 3299^2 + 8374^2 .

It is not a de Polignac number, because 81007277 - 2²² = 76812973 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 (81007271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23573 + ... + 26789.

It is an arithmetic number, because the mean of its divisors is an integer number (7361175).

Almost surely, 2^81007277 is an apocalyptic number.

It is an amenable number.

81007277 is a deficient number, since it is larger than the sum of its proper divisors (7326823).

81007277 is a wasteful number, since it uses less digits than its factorization.

81007277 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3392 (or 3379 counting only the distinct ones).

The product of its (nonzero) digits is 5488, while the sum is 32.

The square root of 81007277 is about 9000.4042686982. The cubic root of 81007277 is about 432.6878278031.

The spelling of 81007277 in words is "eighty-one million, seven thousand, two hundred seventy-seven".