81771078 has 8 divisors (see below), whose sum is σ = 163542168. Its totient is φ = 27257024.

The previous prime is 81771077. The next prime is 81771113. The reversal of 81771078 is 87017718.

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

81771078 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81771077) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6814251 + ... + 6814262.

It is an arithmetic number, because the mean of its divisors is an integer number (20442771).

Almost surely, 2^81771078 is an apocalyptic number.

81771078 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81771078 is a wasteful number, since it uses less digits than its factorization.

81771078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13628518.

The product of its (nonzero) digits is 21952, while the sum is 39.

The square root of 81771078 is about 9042.7362009516. The cubic root of 81771078 is about 434.0434842143.

The spelling of 81771078 in words is "eighty-one million, seven hundred seventy-one thousand, seventy-eight".