81778108 has 12 divisors (see below), whose sum is σ = 146602512. Its totient is φ = 39891680.

The previous prime is 81778097. The next prime is 81778111. The reversal of 81778108 is 80187718.

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, 249160 + ... + 249487.

It is an arithmetic number, because the mean of its divisors is an integer number (12216876).

Almost surely, 2^81778108 is an apocalyptic number.

It is an amenable number.

81778108 is a deficient number, since it is larger than the sum of its proper divisors (64824404).

81778108 is a wasteful number, since it uses less digits than its factorization.

81778108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498692 (or 498690 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 40.

The square root of 81778108 is about 9043.1249023775. The cubic root of 81778108 is about 434.0559223458.

The spelling of 81778108 in words is "eighty-one million, seven hundred seventy-eight thousand, one hundred eight".