81703765 has 32 divisors (see below), whose sum is σ = 115920000. Its totient is φ = 54501120.

The previous prime is 81703729. The next prime is 81703771. The reversal of 81703765 is 56730718.

It is not a de Polignac number, because 81703765 - 2⁷ = 81703637 is a prime.

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, 163486 + ... + 163984.

It is an arithmetic number, because the mean of its divisors is an integer number (3622500).

Almost surely, 2^81703765 is an apocalyptic number.

It is an amenable number.

81703765 is a deficient number, since it is larger than the sum of its proper divisors (34216235).

81703765 is a wasteful number, since it uses less digits than its factorization.

81703765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757.

The product of its (nonzero) digits is 35280, while the sum is 37.

The square root of 81703765 is about 9039.0134970582. The cubic root of 81703765 is about 433.9243516701.

It can be divided in two parts, 8170 and 3765, that added together give a triangular number (11935 = T₁₅₄).

The spelling of 81703765 in words is "eighty-one million, seven hundred three thousand, seven hundred sixty-five".