311421221 has 4 divisors (see below), whose sum is σ = 314444832. Its totient is φ = 308397612.

The previous prime is 311421211. The next prime is 311421241. The reversal of 311421221 is 122124113.

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 an emirpimes, since its reverse is a distinct semiprime: 122124113 = 103 ⋅1185671.

It is a cyclic number.

It is not a de Polignac number, because 311421221 - 2¹⁸ = 311159077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 311421221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (311421211) 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, 1511651 + ... + 1511856.

It is an arithmetic number, because the mean of its divisors is an integer number (78611208).

Almost surely, 2^311421221 is an apocalyptic number.

It is an amenable number.

311421221 is a deficient number, since it is larger than the sum of its proper divisors (3023611).

311421221 is a wasteful number, since it uses less digits than its factorization.

311421221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3023610.

The product of its digits is 96, while the sum is 17.

The square root of 311421221 is about 17647.1306732851. The cubic root of 311421221 is about 677.8226354188.

Adding to 311421221 its reverse (122124113), we get a palindrome (433545334).

The spelling of 311421221 in words is "three hundred eleven million, four hundred twenty-one thousand, two hundred twenty-one".