81304263 has 16 divisors (see below), whose sum is σ = 120929760. Its totient is φ = 53987328.

The previous prime is 81304247. The next prime is 81304273. The reversal of 81304263 is 36240318.

It is a happy number.

It is not a de Polignac number, because 81304263 - 2⁴ = 81304247 is a prime.

It is a super-2 number, since 2×81304263² = 13220766363946338, 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 (81304213) 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, 1081 + ... + 12797.

It is an arithmetic number, because the mean of its divisors is an integer number (7558110).

Almost surely, 2^81304263 is an apocalyptic number.

81304263 is a deficient number, since it is larger than the sum of its proper divisors (39625497).

81304263 is a wasteful number, since it uses less digits than its factorization.

81304263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11983 (or 11977 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 81304263 is about 9016.8876559487. The cubic root of 81304263 is about 433.2159511779.

The spelling of 81304263 in words is "eighty-one million, three hundred four thousand, two hundred sixty-three".