1553319997 has 2 divisors, whose sum is σ = 1553319998. Its totient is φ = 1553319996.

The previous prime is 1553319983. The next prime is 1553320009. The reversal of 1553319997 is 7999133551.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1468882276 + 84437721 = 38326^2 + 9189^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553319997 - 2¹⁹ = 1552795709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1553319907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 776659998 + 776659999.

It is an arithmetic number, because the mean of its divisors is an integer number (776659999).

Almost surely, 2^1553319997 is an apocalyptic number.

It is an amenable number.

1553319997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553319997 is an equidigital number, since it uses as much as digits as its factorization.

1553319997 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1148175, while the sum is 52.

The square root of 1553319997 is about 39412.1808201475. The cubic root of 1553319997 is about 1158.1202206742.

The spelling of 1553319997 in words is "one billion, five hundred fifty-three million, three hundred nineteen thousand, nine hundred ninety-seven".