1313203921 has 2 divisors, whose sum is σ = 1313203922. Its totient is φ = 1313203920.

The previous prime is 1313203907. The next prime is 1313203933. The reversal of 1313203921 is 1293023131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1291683600 + 21520321 = 35940^2 + 4639^2 .

It is a cyclic number.

It is not a de Polignac number, because 1313203921 - 2¹³ = 1313195729 is a prime.

It is not a weakly prime, because it can be changed into another prime (1313203621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656601960 + 656601961.

It is an arithmetic number, because the mean of its divisors is an integer number (656601961).

Almost surely, 2^1313203921 is an apocalyptic number.

It is an amenable number.

1313203921 is a deficient number, since it is larger than the sum of its proper divisors (1).

1313203921 is an equidigital number, since it uses as much as digits as its factorization.

1313203921 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 25.

The square root of 1313203921 is about 36238.1555960013. The cubic root of 1313203921 is about 1095.0754855769.

The spelling of 1313203921 in words is "one billion, three hundred thirteen million, two hundred three thousand, nine hundred twenty-one".