81249356 has 12 divisors (see below), whose sum is σ = 142598568. Its totient is φ = 40506912.

The previous prime is 81249293. The next prime is 81249361. The reversal of 81249356 is 65394218.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27881 + ... + 30656.

It is an arithmetic number, because the mean of its divisors is an integer number (11883214).

Almost surely, 2^81249356 is an apocalyptic number.

It is an amenable number.

81249356 is a deficient number, since it is larger than the sum of its proper divisors (61349212).

81249356 is a wasteful number, since it uses less digits than its factorization.

81249356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58888 (or 58886 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 81249356 is about 9013.8424658966. The cubic root of 81249356 is about 433.1184083434.

The spelling of 81249356 in words is "eighty-one million, two hundred forty-nine thousand, three hundred fifty-six".