81070357 has 4 divisors (see below), whose sum is σ = 81089856. Its totient is φ = 81050860.

The previous prime is 81070349. The next prime is 81070361. The reversal of 81070357 is 75307018.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81070357 - 2³ = 81070349 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81070387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 733 + ... + 12754.

It is an arithmetic number, because the mean of its divisors is an integer number (20272464).

Almost surely, 2^81070357 is an apocalyptic number.

It is an amenable number.

81070357 is a deficient number, since it is larger than the sum of its proper divisors (19499).

81070357 is a wasteful number, since it uses less digits than its factorization.

81070357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19498.

The product of its (nonzero) digits is 5880, while the sum is 31.

The square root of 81070357 is about 9003.9078738068. The cubic root of 81070357 is about 432.8001093483.

The spelling of 81070357 in words is "eighty-one million, seventy thousand, three hundred fifty-seven".