81257467 has 4 divisors (see below), whose sum is σ = 86037336. Its totient is φ = 76477600.

The previous prime is 81257447. The next prime is 81257483. The reversal of 81257467 is 76475218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76475218 = 2 ⋅38237609.

It is a cyclic number.

It is not a de Polignac number, because 81257467 - 2⁷ = 81257339 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81257447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2389909 + ... + 2389942.

It is an arithmetic number, because the mean of its divisors is an integer number (21509334).

Almost surely, 2^81257467 is an apocalyptic number.

81257467 is a deficient number, since it is larger than the sum of its proper divisors (4779869).

81257467 is a wasteful number, since it uses less digits than its factorization.

81257467 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4779868.

The product of its digits is 94080, while the sum is 40.

The square root of 81257467 is about 9014.2923737807. The cubic root of 81257467 is about 433.1328203818.

The spelling of 81257467 in words is "eighty-one million, two hundred fifty-seven thousand, four hundred sixty-seven".