81536470 has 16 divisors (see below), whose sum is σ = 146973168. Its totient is φ = 32568480.

The previous prime is 81536459. The next prime is 81536491. The reversal of 81536470 is 7463518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2185 + ... + 12955.

It is an arithmetic number, because the mean of its divisors is an integer number (9185823).

Almost surely, 2^81536470 is an apocalyptic number.

81536470 is a deficient number, since it is larger than the sum of its proper divisors (65436698).

81536470 is a wasteful number, since it uses less digits than its factorization.

81536470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11535.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 81536470 is about 9029.7547032021. The cubic root of 81536470 is about 433.6279843494.

Adding to 81536470 its reverse (7463518), we get a palindrome (88999988).

The spelling of 81536470 in words is "eighty-one million, five hundred thirty-six thousand, four hundred seventy".