81582650 has 24 divisors (see below), whose sum is σ = 152400960. Its totient is φ = 32491760.

The previous prime is 81582629. The next prime is 81582659. The reversal of 81582650 is 5628518.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81582650.

It is not an unprimeable number, because it can be changed into a prime (81582659) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8537 + ... + 15363.

It is an arithmetic number, because the mean of its divisors is an integer number (6350040).

Almost surely, 2^81582650 is an apocalyptic number.

81582650 is a deficient number, since it is larger than the sum of its proper divisors (70818310).

81582650 is a wasteful number, since it uses less digits than its factorization.

81582650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7078 (or 7073 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 35.

The square root of 81582650 is about 9032.3114428146. The cubic root of 81582650 is about 433.7098338620.

The spelling of 81582650 in words is "eighty-one million, five hundred eighty-two thousand, six hundred fifty".