311605421 has 4 divisors (see below), whose sum is σ = 311643552. Its totient is φ = 311567292.

The previous prime is 311605417. The next prime is 311605423. The reversal of 311605421 is 124506113.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 311605421 - 2² = 311605417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311605423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1271 + ... + 24996.

It is an arithmetic number, because the mean of its divisors is an integer number (77910888).

Almost surely, 2^311605421 is an apocalyptic number.

It is an amenable number.

311605421 is a deficient number, since it is larger than the sum of its proper divisors (38131).

311605421 is a wasteful number, since it uses less digits than its factorization.

311605421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38130.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 311605421 is about 17652.3488805315. The cubic root of 311605421 is about 677.9562490078.

The spelling of 311605421 in words is "three hundred eleven million, six hundred five thousand, four hundred twenty-one".