81211010 has 16 divisors (see below), whose sum is σ = 150895872. Its totient is φ = 31436400.

The previous prime is 81211003. The next prime is 81211027. The reversal of 81211010 is 1011218.

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, 130676 + ... + 131295.

It is an arithmetic number, because the mean of its divisors is an integer number (9430992).

Almost surely, 2^81211010 is an apocalyptic number.

81211010 is a deficient number, since it is larger than the sum of its proper divisors (69684862).

81211010 is a wasteful number, since it uses less digits than its factorization.

81211010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262009.

The product of its (nonzero) digits is 16, while the sum is 14.

The square root of 81211010 is about 9011.7151530660. The cubic root of 81211010 is about 433.0502602259.

Adding to 81211010 its reverse (1011218), we get a palindrome (82222228).

The spelling of 81211010 in words is "eighty-one million, two hundred eleven thousand, ten".