1315351621 has 2 divisors, whose sum is σ = 1315351622. Its totient is φ = 1315351620.

The previous prime is 1315351561. The next prime is 1315351643. The reversal of 1315351621 is 1261535131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1285222500 + 30129121 = 35850^2 + 5489^2 .

It is a cyclic number.

It is not a de Polignac number, because 1315351621 - 2¹⁵ = 1315318853 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1315351621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1315351651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 657675810 + 657675811.

It is an arithmetic number, because the mean of its divisors is an integer number (657675811).

Almost surely, 2^1315351621 is an apocalyptic number.

It is an amenable number.

1315351621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1315351621 is an equidigital number, since it uses as much as digits as its factorization.

1315351621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 28.

The square root of 1315351621 is about 36267.7766205760. The cubic root of 1315351621 is about 1095.6721465623.

Adding to 1315351621 its reverse (1261535131), we get a palindrome (2576886752).

The spelling of 1315351621 in words is "one billion, three hundred fifteen million, three hundred fifty-one thousand, six hundred twenty-one".