81458247 has 16 divisors (see below), whose sum is σ = 117397728. Its totient is φ = 49943040.

The previous prime is 81458233. The next prime is 81458281. The reversal of 81458247 is 74285418.

It is a happy number.

It is not a de Polignac number, because 81458247 - 2¹⁴ = 81441863 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81458287) 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, 7243 + ... + 14675.

It is an arithmetic number, because the mean of its divisors is an integer number (7337358).

Almost surely, 2^81458247 is an apocalyptic number.

81458247 is a deficient number, since it is larger than the sum of its proper divisors (35939481).

81458247 is a wasteful number, since it uses less digits than its factorization.

81458247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7730.

The product of its digits is 71680, while the sum is 39.

The square root of 81458247 is about 9025.4222615898. The cubic root of 81458247 is about 433.4892712284.

The spelling of 81458247 in words is "eighty-one million, four hundred fifty-eight thousand, two hundred forty-seven".