81574791 has 16 divisors (see below), whose sum is σ = 111646080. Its totient is φ = 52958880.

The previous prime is 81574783. The next prime is 81574793. The reversal of 81574791 is 19747518.

It is not a de Polignac number, because 81574791 - 2³ = 81574783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81574793) 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, 20256 + ... + 23946.

It is an arithmetic number, because the mean of its divisors is an integer number (6977880).

Almost surely, 2^81574791 is an apocalyptic number.

81574791 is a deficient number, since it is larger than the sum of its proper divisors (30071289).

81574791 is a wasteful number, since it uses less digits than its factorization.

81574791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3886.

The product of its digits is 70560, while the sum is 42.

The square root of 81574791 is about 9031.8763831222. The cubic root of 81574791 is about 433.6959067380.

The spelling of 81574791 in words is "eighty-one million, five hundred seventy-four thousand, seven hundred ninety-one".