81878776 has 32 divisors (see below), whose sum is σ = 175805280. Its totient is φ = 35020800.

The previous prime is 81878759. The next prime is 81878777. The reversal of 81878776 is 67787818.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81878777) 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, 34756 + ... + 37036.

It is an arithmetic number, because the mean of its divisors is an integer number (5493915).

Almost surely, 2^81878776 is an apocalyptic number.

It is an amenable number.

81878776 is an abundant number, since it is smaller than the sum of its proper divisors (93926504).

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

81878776 is a wasteful number, since it uses less digits than its factorization.

81878776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2935 (or 2931 counting only the distinct ones).

The product of its digits is 1053696, while the sum is 52.

The square root of 81878776 is about 9048.6891868381. The cubic root of 81878776 is about 434.2339554214.

The spelling of 81878776 in words is "eighty-one million, eight hundred seventy-eight thousand, seven hundred seventy-six".