81861379248 has 40 divisors (see below), whose sum is σ = 230700252096. Its totient is φ = 24806478400.

The previous prime is 81861379241. The next prime is 81861379253. The reversal of 81861379248 is 84297316818.

It is not an unprimeable number, because it can be changed into a prime (81861379241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77519718 + ... + 77520773.

Almost surely, 2^81861379248 is an apocalyptic number.

81861379248 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

81861379248 is an abundant number, since it is smaller than the sum of its proper divisors (148838872848).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81861379248 is a wasteful number, since it uses less digits than its factorization.

81861379248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155040513 (or 155040507 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 57.

The spelling of 81861379248 in words is "eighty-one billion, eight hundred sixty-one million, three hundred seventy-nine thousand, two hundred forty-eight".