81356606 has 4 divisors (see below), whose sum is σ = 122034912. Its totient is φ = 40678302.

The previous prime is 81356593. The next prime is 81356621. The reversal of 81356606 is 60665318.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20339150 + ... + 20339153.

It is an arithmetic number, because the mean of its divisors is an integer number (30508728).

Almost surely, 2^81356606 is an apocalyptic number.

81356606 is a deficient number, since it is larger than the sum of its proper divisors (40678306).

81356606 is a wasteful number, since it uses less digits than its factorization.

81356606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40678305.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 81356606 is about 9019.7896871269. The cubic root of 81356606 is about 433.3088981619.

It can be divided in two parts, 8135 and 6606, that added together give a palindrome (14741).

The spelling of 81356606 in words is "eighty-one million, three hundred fifty-six thousand, six hundred six".