1553315521 has 2 divisors, whose sum is σ = 1553315522. Its totient is φ = 1553315520.

The previous prime is 1553315513. The next prime is 1553315563. The reversal of 1553315521 is 1255133551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1538600625 + 14714896 = 39225^2 + 3836^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553315521 - 2³ = 1553315513 is a prime.

It is not a weakly prime, because it can be changed into another prime (1553315501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 776657760 + 776657761.

It is an arithmetic number, because the mean of its divisors is an integer number (776657761).

Almost surely, 2^1553315521 is an apocalyptic number.

It is an amenable number.

1553315521 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553315521 is an equidigital number, since it uses as much as digits as its factorization.

1553315521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11250, while the sum is 31.

The square root of 1553315521 is about 39412.1240356315. The cubic root of 1553315521 is about 1158.1191082717.

The spelling of 1553315521 in words is "one billion, five hundred fifty-three million, three hundred fifteen thousand, five hundred twenty-one".