311213857 has 8 divisors (see below), whose sum is σ = 314594280. Its totient is φ = 307843200.

The previous prime is 311213797. The next prime is 311213879. The reversal of 311213857 is 758312113.

It can be written as a sum of positive squares in 4 ways, for example, as 64064016 + 247149841 = 8004^2 + 15721^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 311213857 - 2¹⁵ = 311181089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (311213257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74373 + ... + 78445.

It is an arithmetic number, because the mean of its divisors is an integer number (39324285).

Almost surely, 2^311213857 is an apocalyptic number.

It is an amenable number.

311213857 is a deficient number, since it is larger than the sum of its proper divisors (3380423).

311213857 is a wasteful number, since it uses less digits than its factorization.

311213857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4883.

The product of its digits is 5040, while the sum is 31.

The square root of 311213857 is about 17641.2544055121. The cubic root of 311213857 is about 677.6721562478.

Subtracting from 311213857 its sum of digits (31), we obtain a triangular number (311213826 = T₂₄₉₄₈).

The spelling of 311213857 in words is "three hundred eleven million, two hundred thirteen thousand, eight hundred fifty-seven".