1553121403 has 2 divisors, whose sum is σ = 1553121404. Its totient is φ = 1553121402.

The previous prime is 1553121341. The next prime is 1553121413. The reversal of 1553121403 is 3041213551.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (3041213551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1553121403 - 2¹⁷ = 1552990331 is a prime.

It is not a weakly prime, because it can be changed into another prime (1553121413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 776560701 + 776560702.

It is an arithmetic number, because the mean of its divisors is an integer number (776560702).

Almost surely, 2^1553121403 is an apocalyptic number.

1553121403 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553121403 is an equidigital number, since it uses as much as digits as its factorization.

1553121403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 1553121403 is about 39409.6612900948. The cubic root of 1553121403 is about 1158.0708628407.

Adding to 1553121403 its reverse (3041213551), we get a palindrome (4594334954).

The spelling of 1553121403 in words is "one billion, five hundred fifty-three million, one hundred twenty-one thousand, four hundred three".