1553421421 has 2 divisors, whose sum is σ = 1553421422. Its totient is φ = 1553421420.

The previous prime is 1553421413. The next prime is 1553421433. The reversal of 1553421421 is 1241243551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1324232100 + 229189321 = 36390^2 + 15139^2 .

It is a cyclic number.

It is not a de Polignac number, because 1553421421 - 2³ = 1553421413 is a prime.

It is a super-2 number, since 2×1553421421² = 4826236222443318482, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1553421421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1553421481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 776710710 + 776710711.

It is an arithmetic number, because the mean of its divisors is an integer number (776710711).

Almost surely, 2^1553421421 is an apocalyptic number.

It is an amenable number.

1553421421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1553421421 is an equidigital number, since it uses as much as digits as its factorization.

1553421421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4800, while the sum is 28.

The square root of 1553421421 is about 39413.4675079471. The cubic root of 1553421421 is about 1158.1454266050.

Adding to 1553421421 its reverse (1241243551), we get a palindrome (2794664972).

The spelling of 1553421421 in words is "one billion, five hundred fifty-three million, four hundred twenty-one thousand, four hundred twenty-one".