1553661269 has 2 divisors, whose sum is σ = 1553661270. Its totient is φ = 1553661268.

The previous prime is 1553661259. The next prime is 1553661289. The reversal of 1553661269 is 9621663551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1119772369 + 433888900 = 33463^2 + 20830^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1553661269 is a prime.

It is a super-2 number, since 2×1553661269² = 4827726677581380722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1553661209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 776830634 + 776830635.

It is an arithmetic number, because the mean of its divisors is an integer number (776830635).

Almost surely, 2^1553661269 is an apocalyptic number.

It is an amenable number.

1553661269 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553661269 is an equidigital number, since it uses as much as digits as its factorization.

1553661269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 291600, while the sum is 44.

The square root of 1553661269 is about 39416.5101068068. The cubic root of 1553661269 is about 1158.2050293557.

The spelling of 1553661269 in words is "one billion, five hundred fifty-three million, six hundred sixty-one thousand, two hundred sixty-nine".