81378233272 has 32 divisors (see below), whose sum is σ = 175492660320. Its totient is φ = 34654239360.

The previous prime is 81378233267. The next prime is 81378233273. The reversal of 81378233272 is 27233287318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81378233273) 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, 4619179 + ... + 4636762.

It is an arithmetic number, because the mean of its divisors is an integer number (5484145635).

Almost surely, 2^81378233272 is an apocalyptic number.

It is an amenable number.

81378233272 is an abundant number, since it is smaller than the sum of its proper divisors (94114427048).

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

81378233272 is a wasteful number, since it uses less digits than its factorization.

81378233272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9256111 (or 9256107 counting only the distinct ones).

The product of its digits is 677376, while the sum is 46.

The spelling of 81378233272 in words is "eighty-one billion, three hundred seventy-eight million, two hundred thirty-three thousand, two hundred seventy-two".