81503685 has 16 divisors (see below), whose sum is σ = 144895680. Its totient is φ = 43468560.

The previous prime is 81503663. The next prime is 81503689. The reversal of 81503685 is 58630518.

It is not a de Polignac number, because 81503685 - 2⁶ = 81503621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81503689) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 301731 + ... + 302000.

It is an arithmetic number, because the mean of its divisors is an integer number (9055980).

Almost surely, 2^81503685 is an apocalyptic number.

It is an amenable number.

81503685 is a deficient number, since it is larger than the sum of its proper divisors (63391995).

81503685 is a wasteful number, since it uses less digits than its factorization.

81503685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603745 (or 603739 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 81503685 is about 9027.9391336008. The cubic root of 81503685 is about 433.5698573978.

The spelling of 81503685 in words is "eighty-one million, five hundred three thousand, six hundred eighty-five".