81245856 has 48 divisors (see below), whose sum is σ = 225820224. Its totient is φ = 25488384.

The previous prime is 81245833. The next prime is 81245863. The reversal of 81245856 is 65854218.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23260 + ... + 26523.

It is an arithmetic number, because the mean of its divisors is an integer number (4704588).

Almost surely, 2^81245856 is an apocalyptic number.

It is an amenable number.

81245856 is an abundant number, since it is smaller than the sum of its proper divisors (144574368).

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

81245856 is a wasteful number, since it uses less digits than its factorization.

81245856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49813 (or 49805 counting only the distinct ones).

The product of its digits is 76800, while the sum is 39.

The square root of 81245856 is about 9013.6483179676. The cubic root of 81245856 is about 433.1121890686.

The spelling of 81245856 in words is "eighty-one million, two hundred forty-five thousand, eight hundred fifty-six".