1213100321 has 2 divisors, whose sum is σ = 1213100322. Its totient is φ = 1213100320.

The previous prime is 1213100311. The next prime is 1213100341. The reversal of 1213100321 is 1230013121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 883278400 + 329821921 = 29720^2 + 18161^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213100321 - 2⁶ = 1213100257 is a prime.

It is a super-2 number, since 2×1213100321² = 2943224777620606082, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1213100296 and 1213100305.

It is not a weakly prime, because it can be changed into another prime (1213100311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606550160 + 606550161.

It is an arithmetic number, because the mean of its divisors is an integer number (606550161).

Almost surely, 2^1213100321 is an apocalyptic number.

It is an amenable number.

1213100321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1213100321 is an equidigital number, since it uses as much as digits as its factorization.

1213100321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 1213100321 is about 34829.5897334436. The cubic root of 1213100321 is about 1066.5115732296.

Adding to 1213100321 its reverse (1230013121), we get a palindrome (2443113442).

The spelling of 1213100321 in words is "one billion, two hundred thirteen million, one hundred thousand, three hundred twenty-one".