312620221 has 4 divisors (see below), whose sum is σ = 312655612. Its totient is φ = 312584832.

The previous prime is 312620201. The next prime is 312620257. The reversal of 312620221 is 122026213.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 167417721 + 145202500 = 12939^2 + 12050^2 .

It is a cyclic number.

It is not a de Polignac number, because 312620221 - 2¹⁵ = 312587453 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (312620201) 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, 7795 + ... + 26191.

It is an arithmetic number, because the mean of its divisors is an integer number (78163903).

Almost surely, 2^312620221 is an apocalyptic number.

It is an amenable number.

312620221 is a deficient number, since it is larger than the sum of its proper divisors (35391).

312620221 is a wasteful number, since it uses less digits than its factorization.

312620221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35390.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 312620221 is about 17681.0695660642. The cubic root of 312620221 is about 678.6914143253.

Adding to 312620221 its reverse (122026213), we get a palindrome (434646434).

The spelling of 312620221 in words is "three hundred twelve million, six hundred twenty thousand, two hundred twenty-one".