81302265 has 64 divisors (see below), whose sum is σ = 160807680. Its totient is φ = 38638080.

The previous prime is 81302237. The next prime is 81302269. The reversal of 81302265 is 56220318.

It is not a de Polignac number, because 81302265 - 2⁵ = 81302233 is a prime.

It is a super-2 number, since 2×81302265² = 13220116588260450, which contains 22 as substring.

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 (81302269) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 78189 + ... + 79221.

It is an arithmetic number, because the mean of its divisors is an integer number (2512620).

Almost surely, 2^81302265 is an apocalyptic number.

It is an amenable number.

81302265 is a deficient number, since it is larger than the sum of its proper divisors (79505415).

81302265 is a wasteful number, since it uses less digits than its factorization.

81302265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111 (or 1105 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 81302265 is about 9016.7768631590. The cubic root of 81302265 is about 433.2124024810.

The spelling of 81302265 in words is "eighty-one million, three hundred two thousand, two hundred sixty-five".