81478028 has 6 divisors (see below), whose sum is σ = 142586556. Its totient is φ = 40739012.

The previous prime is 81478009. The next prime is 81478031. The reversal of 81478028 is 82087418.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81477982 and 81478000.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10184750 + ... + 10184757.

It is an arithmetic number, because the mean of its divisors is an integer number (23764426).

Almost surely, 2^81478028 is an apocalyptic number.

It is an amenable number.

81478028 is a deficient number, since it is larger than the sum of its proper divisors (61108528).

81478028 is a wasteful number, since it uses less digits than its factorization.

81478028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20369511 (or 20369509 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 38.

The square root of 81478028 is about 9026.5180440744. The cubic root of 81478028 is about 433.5243573312.

The spelling of 81478028 in words is "eighty-one million, four hundred seventy-eight thousand, twenty-eight".