81605702 has 32 divisors (see below), whose sum is σ = 133539840. Its totient is φ = 37287360.

The previous prime is 81605659. The next prime is 81605707. The reversal of 81605702 is 20750618.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81605707) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 126593 + ... + 127235.

It is an arithmetic number, because the mean of its divisors is an integer number (4173120).

Almost surely, 2^81605702 is an apocalyptic number.

81605702 is a deficient number, since it is larger than the sum of its proper divisors (51934138).

81605702 is a wasteful number, since it uses less digits than its factorization.

81605702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 81605702 is about 9033.5874380005. The cubic root of 81605702 is about 433.7506797100.

The spelling of 81605702 in words is "eighty-one million, six hundred five thousand, seven hundred two".