81577473 has 8 divisors (see below), whose sum is σ = 108927936. Its totient is φ = 54306000.

The previous prime is 81577459. The next prime is 81577487. The reversal of 81577473 is 37477518.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81577459) and next prime (81577487).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81577473 - 2¹² = 81573377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81577403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17293 + ... + 21498.

It is an arithmetic number, because the mean of its divisors is an integer number (13615992).

Almost surely, 2^81577473 is an apocalyptic number.

It is an amenable number.

81577473 is a deficient number, since it is larger than the sum of its proper divisors (27350463).

81577473 is a wasteful number, since it uses less digits than its factorization.

81577473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39495.

The product of its digits is 164640, while the sum is 42.

The square root of 81577473 is about 9032.0248560331. The cubic root of 81577473 is about 433.7006596756.

The spelling of 81577473 in words is "eighty-one million, five hundred seventy-seven thousand, four hundred seventy-three".