81177485 has 4 divisors (see below), whose sum is σ = 97412988. Its totient is φ = 64941984.

The previous prime is 81177469. The next prime is 81177539. The reversal of 81177485 is 58477118.

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 22486564 + 58690921 = 4742^2 + 7661^2 .

It is a cyclic number.

It is not a de Polignac number, because 81177485 - 2⁴ = 81177469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8117744 + ... + 8117753.

It is an arithmetic number, because the mean of its divisors is an integer number (24353247).

Almost surely, 2^81177485 is an apocalyptic number.

It is an amenable number.

81177485 is a deficient number, since it is larger than the sum of its proper divisors (16235503).

81177485 is a wasteful number, since it uses less digits than its factorization.

81177485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16235502.

The product of its digits is 62720, while the sum is 41.

The square root of 81177485 is about 9009.8548822942. The cubic root of 81177485 is about 432.9906623620.

The spelling of 81177485 in words is "eighty-one million, one hundred seventy-seven thousand, four hundred eighty-five".