81704895 has 32 divisors (see below), whose sum is σ = 133056000. Its totient is φ = 42808704.

The previous prime is 81704869. The next prime is 81704899. The reversal of 81704895 is 59840718.

It is not a de Polignac number, because 81704895 - 2⁵ = 81704863 is a prime.

It is a super-2 number, since 2×81704895² = 13351379733922050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81704899) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 310534 + ... + 310796.

It is an arithmetic number, because the mean of its divisors is an integer number (4158000).

Almost surely, 2^81704895 is an apocalyptic number.

81704895 is a deficient number, since it is larger than the sum of its proper divisors (51351105).

81704895 is a wasteful number, since it uses less digits than its factorization.

81704895 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 559.

The product of its (nonzero) digits is 80640, while the sum is 42.

The square root of 81704895 is about 9039.0760036632. The cubic root of 81704895 is about 433.9263521175.

The spelling of 81704895 in words is "eighty-one million, seven hundred four thousand, eight hundred ninety-five".