81321735 has 32 divisors (see below), whose sum is σ = 142467840. Its totient is φ = 39283200.

The previous prime is 81321697. The next prime is 81321743. The reversal of 81321735 is 53712318.

It is not a de Polignac number, because 81321735 - 2⁹ = 81321223 is a prime.

It is a super-2 number, since 2×81321735² = 13226449166820450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53871 + ... + 55359.

It is an arithmetic number, because the mean of its divisors is an integer number (4452120).

Almost surely, 2^81321735 is an apocalyptic number.

81321735 is a deficient number, since it is larger than the sum of its proper divisors (61146105).

81321735 is a wasteful number, since it uses less digits than its factorization.

81321735 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1839.

The product of its digits is 5040, while the sum is 30.

The square root of 81321735 is about 9017.8564526167. The cubic root of 81321735 is about 433.2469811497.

The spelling of 81321735 in words is "eighty-one million, three hundred twenty-one thousand, seven hundred thirty-five".