81903575 has 24 divisors (see below), whose sum is σ = 114138528. Its totient is φ = 57847680.

The previous prime is 81903553. The next prime is 81903583. The reversal of 81903575 is 57530918.

It is not a de Polignac number, because 81903575 - 2¹² = 81899479 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1997 + ... + 12953.

It is an arithmetic number, because the mean of its divisors is an integer number (4755772).

Almost surely, 2^81903575 is an apocalyptic number.

81903575 is a deficient number, since it is larger than the sum of its proper divisors (32234953).

81903575 is a wasteful number, since it uses less digits than its factorization.

81903575 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11003 (or 10998 counting only the distinct ones).

The product of its (nonzero) digits is 37800, while the sum is 38.

The square root of 81903575 is about 9050.0593920703. The cubic root of 81903575 is about 434.2777904720.

The spelling of 81903575 in words is "eighty-one million, nine hundred three thousand, five hundred seventy-five".