81570674 has 4 divisors (see below), whose sum is σ = 122356014. Its totient is φ = 40785336.

The previous prime is 81570637. The next prime is 81570677. The reversal of 81570674 is 47607518.

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., 75777025 + 5793649 = 8705^2 + 2407^2 .

It is not an unprimeable number, because it can be changed into a prime (81570677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20392667 + ... + 20392670.

Almost surely, 2^81570674 is an apocalyptic number.

81570674 is a deficient number, since it is larger than the sum of its proper divisors (40785340).

81570674 is a wasteful number, since it uses less digits than its factorization.

81570674 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40785339.

The product of its (nonzero) digits is 47040, while the sum is 38.

The square root of 81570674 is about 9031.6484652582. The cubic root of 81570674 is about 433.6886105457.

The spelling of 81570674 in words is "eighty-one million, five hundred seventy thousand, six hundred seventy-four".