311906213 has 2 divisors, whose sum is σ = 311906214. Its totient is φ = 311906212.

The previous prime is 311906207. The next prime is 311906227. The reversal of 311906213 is 312609113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 175880644 + 136025569 = 13262^2 + 11663^2 .

It is a cyclic number.

It is not a de Polignac number, because 311906213 - 2¹⁶ = 311840677 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (311906713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155953106 + 155953107.

It is an arithmetic number, because the mean of its divisors is an integer number (155953107).

Almost surely, 2^311906213 is an apocalyptic number.

It is an amenable number.

311906213 is a deficient number, since it is larger than the sum of its proper divisors (1).

311906213 is an equidigital number, since it uses as much as digits as its factorization.

311906213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 311906213 is about 17660.8667114612. The cubic root of 311906213 is about 678.1743220598.

The spelling of 311906213 in words is "three hundred eleven million, nine hundred six thousand, two hundred thirteen".