81727974 has 32 divisors (see below), whose sum is σ = 187884000. Its totient is φ = 26302752.

The previous prime is 81727967. The next prime is 81727979. The reversal of 81727974 is 47972718.

It is a happy 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 (81727979) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24529 + ... + 27660.

It is an arithmetic number, because the mean of its divisors is an integer number (5871375).

Almost surely, 2^81727974 is an apocalyptic number.

81727974 is an abundant number, since it is smaller than the sum of its proper divisors (106156026).

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

81727974 is a wasteful number, since it uses less digits than its factorization.

81727974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52229 (or 52223 counting only the distinct ones).

The product of its digits is 197568, while the sum is 45.

The square root of 81727974 is about 9040.3525373738. The cubic root of 81727974 is about 433.9672050085.

The spelling of 81727974 in words is "eighty-one million, seven hundred twenty-seven thousand, nine hundred seventy-four".