81140265 has 16 divisors (see below), whose sum is σ = 144249600. Its totient is φ = 43274736.

The previous prime is 81140263. The next prime is 81140329. The reversal of 81140265 is 56204118.

It is not a de Polignac number, because 81140265 - 2¹ = 81140263 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81140263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 300385 + ... + 300654.

It is an arithmetic number, because the mean of its divisors is an integer number (9015600).

Almost surely, 2^81140265 is an apocalyptic number.

It is an amenable number.

81140265 is a deficient number, since it is larger than the sum of its proper divisors (63109335).

81140265 is a wasteful number, since it uses less digits than its factorization.

81140265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 601053 (or 601047 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 81140265 is about 9007.7891294146. The cubic root of 81140265 is about 432.9244766204.

The spelling of 81140265 in words is "eighty-one million, one hundred forty thousand, two hundred sixty-five".