81350506 has 4 divisors (see below), whose sum is σ = 122025762. Its totient is φ = 40675252.

The previous prime is 81350501. The next prime is 81350513. The reversal of 81350506 is 60505318.

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., 73256481 + 8094025 = 8559^2 + 2845^2 .

It is not an unprimeable number, because it can be changed into a prime (81350501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20337625 + ... + 20337628.

Almost surely, 2^81350506 is an apocalyptic number.

81350506 is a deficient number, since it is larger than the sum of its proper divisors (40675256).

81350506 is a wasteful number, since it uses less digits than its factorization.

81350506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40675255.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 81350506 is about 9019.4515354316. The cubic root of 81350506 is about 433.2980682676.

The spelling of 81350506 in words is "eighty-one million, three hundred fifty thousand, five hundred six".