123421553 has 2 divisors, whose sum is σ = 123421554. Its totient is φ = 123421552.

The previous prime is 123421541. The next prime is 123421559. The reversal of 123421553 is 355124321.

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., 104611984 + 18809569 = 10228^2 + 4337^2 .

It is a cyclic number.

It is not a de Polignac number, because 123421553 - 2¹⁰ = 123420529 is a prime.

It is not a weakly prime, because it can be changed into another prime (123421559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61710776 + 61710777.

It is an arithmetic number, because the mean of its divisors is an integer number (61710777).

Almost surely, 2^123421553 is an apocalyptic number.

It is an amenable number.

123421553 is a deficient number, since it is larger than the sum of its proper divisors (1).

123421553 is an equidigital number, since it uses as much as digits as its factorization.

123421553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3600, while the sum is 26.

The square root of 123421553 is about 11109.5253273936. The cubic root of 123421553 is about 497.8864826770.

Adding to 123421553 its reverse (355124321), we get a palindrome (478545874).

The spelling of 123421553 in words is "one hundred twenty-three million, four hundred twenty-one thousand, five hundred fifty-three".