81200810 has 16 divisors (see below), whose sum is σ = 152516736. Its totient is φ = 31068048.

The previous prime is 81200807. The next prime is 81200827. The reversal of 81200810 is 1800218.

It is a super-2 number, since 2×81200810² = 13187143089312200, which contains 22 as substring.

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 7 ways as a sum of consecutive naturals, for example, 176294 + ... + 176753.

It is an arithmetic number, because the mean of its divisors is an integer number (9532296).

Almost surely, 2^81200810 is an apocalyptic number.

81200810 is a deficient number, since it is larger than the sum of its proper divisors (71315926).

81200810 is a wasteful number, since it uses less digits than its factorization.

81200810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353077.

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 81200810 is about 9011.1492052901. The cubic root of 81200810 is about 433.0321292787.

The spelling of 81200810 in words is "eighty-one million, two hundred thousand, eight hundred ten".