81458169 has 32 divisors (see below), whose sum is σ = 124750080. Its totient is φ = 47114496.

The previous prime is 81458123. The next prime is 81458171. The reversal of 81458169 is 96185418.

It is not a de Polignac number, because 81458169 - 2⁸ = 81457913 is a prime.

It is a super-2 number, since 2×81458169² = 13270866593665122, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81458169.

It is not an unprimeable number, because it can be changed into a prime (81458969) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 111684 + ... + 112410.

It is an arithmetic number, because the mean of its divisors is an integer number (3898440).

Almost surely, 2^81458169 is an apocalyptic number.

It is an amenable number.

81458169 is a deficient number, since it is larger than the sum of its proper divisors (43291911).

81458169 is a wasteful number, since it uses less digits than its factorization.

81458169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786 (or 760 counting only the distinct ones).

The product of its digits is 69120, while the sum is 42.

The square root of 81458169 is about 9025.4179404613. The cubic root of 81458169 is about 433.4891328664.

The spelling of 81458169 in words is "eighty-one million, four hundred fifty-eight thousand, one hundred sixty-nine".