81580346 has 4 divisors (see below), whose sum is σ = 122370522. Its totient is φ = 40790172.

The previous prime is 81580309. The next prime is 81580361. The reversal of 81580346 is 64308518.

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., 72063121 + 9517225 = 8489^2 + 3085^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20395085 + ... + 20395088.

Almost surely, 2^81580346 is an apocalyptic number.

81580346 is a deficient number, since it is larger than the sum of its proper divisors (40790176).

81580346 is a wasteful number, since it uses less digits than its factorization.

81580346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40790175.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 81580346 is about 9032.1838998107. The cubic root of 81580346 is about 433.7057509806.

The spelling of 81580346 in words is "eighty-one million, five hundred eighty thousand, three hundred forty-six".