81975028 has 12 divisors (see below), whose sum is σ = 146792800. Its totient is φ = 40034232.

The previous prime is 81975011. The next prime is 81975029. The reversal of 81975028 is 82057918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81975029) 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, 238128 + ... + 238471.

Almost surely, 2^81975028 is an apocalyptic number.

It is an amenable number.

81975028 is a deficient number, since it is larger than the sum of its proper divisors (64817772).

81975028 is a wasteful number, since it uses less digits than its factorization.

81975028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476646 (or 476644 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 81975028 is about 9054.0061851094. The cubic root of 81975028 is about 434.4040423140.

It can be divided in two parts, 8197 and 5028, that added together give a square (13225 = 115²).

The spelling of 81975028 in words is "eighty-one million, nine hundred seventy-five thousand, twenty-eight".