81712594 has 4 divisors (see below), whose sum is σ = 122568894. Its totient is φ = 40856296.

The previous prime is 81712577. The next prime is 81712639. The reversal of 81712594 is 49521718.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 50765625 + 30946969 = 7125^2 + 5563^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20428147 + ... + 20428150.

Almost surely, 2^81712594 is an apocalyptic number.

81712594 is a deficient number, since it is larger than the sum of its proper divisors (40856300).

81712594 is a wasteful number, since it uses less digits than its factorization.

81712594 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40856299.

The product of its digits is 20160, while the sum is 37.

The square root of 81712594 is about 9039.5018668066. The cubic root of 81712594 is about 433.9399812236.

The spelling of 81712594 in words is "eighty-one million, seven hundred twelve thousand, five hundred ninety-four".