70831309 has 4 divisors (see below), whose sum is σ = 71992540. Its totient is φ = 69670080.

The previous prime is 70831289. The next prime is 70831337. The reversal of 70831309 is 90313807.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90313807 = 911 ⋅99137.

It can be written as a sum of positive squares in 2 ways, for example, as 1108809 + 69722500 = 1053^2 + 8350^2 .

It is a cyclic number.

It is not a de Polignac number, because 70831309 - 2⁷ = 70831181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (70831339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 580524 + ... + 580645.

It is an arithmetic number, because the mean of its divisors is an integer number (17998135).

Almost surely, 2^70831309 is an apocalyptic number.

It is an amenable number.

70831309 is a deficient number, since it is larger than the sum of its proper divisors (1161231).

70831309 is a wasteful number, since it uses less digits than its factorization.

70831309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161230.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 70831309 is about 8416.1338511219. The cubic root of 70831309 is about 413.7535718302.

The spelling of 70831309 in words is "seventy million, eight hundred thirty-one thousand, three hundred nine".