1555117649 has 2 divisors, whose sum is σ = 1555117650. Its totient is φ = 1555117648.

The previous prime is 1555117621. The next prime is 1555117691. The reversal of 1555117649 is 9467115551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1277562049 + 277555600 = 35743^2 + 16660^2 .

It is an emirp because it is prime and its reverse (9467115551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1555117649 - 2²⁰ = 1554069073 is a prime.

It is not a weakly prime, because it can be changed into another prime (1555117549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 777558824 + 777558825.

It is an arithmetic number, because the mean of its divisors is an integer number (777558825).

Almost surely, 2^1555117649 is an apocalyptic number.

It is an amenable number.

1555117649 is a deficient number, since it is larger than the sum of its proper divisors (1).

1555117649 is an equidigital number, since it uses as much as digits as its factorization.

1555117649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 189000, while the sum is 44.

The square root of 1555117649 is about 39434.9800177457. The cubic root of 1555117649 is about 1158.5668113159.

The spelling of 1555117649 in words is "one billion, five hundred fifty-five million, one hundred seventeen thousand, six hundred forty-nine".