81245756 has 6 divisors (see below), whose sum is σ = 142180080. Its totient is φ = 40622876.

The previous prime is 81245753. The next prime is 81245777. The reversal of 81245756 is 65754218.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81245753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10155716 + ... + 10155723.

It is an arithmetic number, because the mean of its divisors is an integer number (23696680).

Almost surely, 2^81245756 is an apocalyptic number.

It is an amenable number.

81245756 is a deficient number, since it is larger than the sum of its proper divisors (60934324).

81245756 is a wasteful number, since it uses less digits than its factorization.

81245756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20311443 (or 20311441 counting only the distinct ones).

The product of its digits is 67200, while the sum is 38.

The square root of 81245756 is about 9013.6427708225. The cubic root of 81245756 is about 433.1120113725.

The spelling of 81245756 in words is "eighty-one million, two hundred forty-five thousand, seven hundred fifty-six".