81678772 has 12 divisors (see below), whose sum is σ = 163357600. Its totient is φ = 35005176.

The previous prime is 81678749. The next prime is 81678781. The reversal of 81678772 is 27787618.

81678772 is an admirable number.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

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, 1458522 + ... + 1458577.

Almost surely, 2^81678772 is an apocalyptic number.

It is an amenable number.

81678772 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.

81678772 is a wasteful number, since it uses less digits than its factorization.

81678772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2917110 (or 2917108 counting only the distinct ones).

The product of its digits is 263424, while the sum is 46.

The square root of 81678772 is about 9037.6308842528. The cubic root of 81678772 is about 433.8801016598.

The spelling of 81678772 in words is "eighty-one million, six hundred seventy-eight thousand, seven hundred seventy-two".