81633233618 has 4 divisors (see below), whose sum is σ = 122449850430. Its totient is φ = 40816616808.

The previous prime is 81633233597. The next prime is 81633233653.

81633233618 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 81594208609 + 39025009 = 285647^2 + 6247^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20408308403 + ... + 20408308406.

Almost surely, 2^81633233618 is an apocalyptic number.

81633233618 is a deficient number, since it is larger than the sum of its proper divisors (40816616812).

81633233618 is a wasteful number, since it uses less digits than its factorization.

81633233618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40816616811.

The product of its digits is 373248, while the sum is 44.

The spelling of 81633233618 in words is "eighty-one billion, six hundred thirty-three million, two hundred thirty-three thousand, six hundred eighteen".