81415587238 has 8 divisors (see below), whose sum is σ = 124125403680. Its totient is φ = 40040452680.

The previous prime is 81415587221. The next prime is 81415587251. The reversal of 81415587238 is 83278551418.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 333670318 + ... + 333670561.

It is an arithmetic number, because the mean of its divisors is an integer number (15515675460).

Almost surely, 2^81415587238 is an apocalyptic number.

81415587238 is a deficient number, since it is larger than the sum of its proper divisors (42709816442).

81415587238 is a wasteful number, since it uses less digits than its factorization.

81415587238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 667340942.

The product of its digits is 2150400, while the sum is 52.

The spelling of 81415587238 in words is "eighty-one billion, four hundred fifteen million, five hundred eighty-seven thousand, two hundred thirty-eight".