81763145 has 4 divisors (see below), whose sum is σ = 98115780. Its totient is φ = 65410512.

The previous prime is 81763141. The next prime is 81763147. The reversal of 81763145 is 54136718.

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 58308496 + 23454649 = 7636^2 + 4843^2 .

It is a cyclic number.

It is not a de Polignac number, because 81763145 - 2² = 81763141 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81763141) 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, 8176310 + ... + 8176319.

It is an arithmetic number, because the mean of its divisors is an integer number (24528945).

Almost surely, 2^81763145 is an apocalyptic number.

It is an amenable number.

81763145 is a deficient number, since it is larger than the sum of its proper divisors (16352635).

81763145 is a wasteful number, since it uses less digits than its factorization.

81763145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16352634.

The product of its digits is 20160, while the sum is 35.

The square root of 81763145 is about 9042.2975509546. The cubic root of 81763145 is about 434.0294475549.

The spelling of 81763145 in words is "eighty-one million, seven hundred sixty-three thousand, one hundred forty-five".