311145521 has 4 divisors (see below), whose sum is σ = 315789552. Its totient is φ = 306501492.

The previous prime is 311145511. The next prime is 311145533. The reversal of 311145521 is 125541113.

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 a de Polignac number, because none of the positive numbers 2^k-311145521 is a prime.

It is a super-2 number, since 2×311145521² = 193623070476722882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (311145511) 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, 2321915 + ... + 2322048.

It is an arithmetic number, because the mean of its divisors is an integer number (78947388).

Almost surely, 2^311145521 is an apocalyptic number.

It is an amenable number.

311145521 is a deficient number, since it is larger than the sum of its proper divisors (4644031).

311145521 is an equidigital number, since it uses as much as digits as its factorization.

311145521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4644030.

The product of its digits is 600, while the sum is 23.

The square root of 311145521 is about 17639.3174754581. The cubic root of 311145521 is about 677.6225517787.

Adding to 311145521 its reverse (125541113), we get a palindrome (436686634).

The spelling of 311145521 in words is "three hundred eleven million, one hundred forty-five thousand, five hundred twenty-one".