81200816 has 10 divisors (see below), whose sum is σ = 157326612. Its totient is φ = 40600400.

The previous prime is 81200807. The next prime is 81200827. The reversal of 81200816 is 61800218.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2537510 + ... + 2537541.

Almost surely, 2^81200816 is an apocalyptic number.

It is an amenable number.

81200816 is a deficient number, since it is larger than the sum of its proper divisors (76125796).

81200816 is a wasteful number, since it uses less digits than its factorization.

81200816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5075059 (or 5075053 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 81200816 is about 9011.1495382110. The cubic root of 81200816 is about 433.0321399444.

The spelling of 81200816 in words is "eighty-one million, two hundred thousand, eight hundred sixteen".