555021421 has 2 divisors, whose sum is σ = 555021422. Its totient is φ = 555021420.

The previous prime is 555021419. The next prime is 555021431. The reversal of 555021421 is 124120555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 548964900 + 6056521 = 23430^2 + 2461^2 .

It is a cyclic number.

It is not a de Polignac number, because 555021421 - 2¹ = 555021419 is a prime.

Together with 555021419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (555021431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 277510710 + 277510711.

It is an arithmetic number, because the mean of its divisors is an integer number (277510711).

Almost surely, 2^555021421 is an apocalyptic number.

It is an amenable number.

555021421 is a deficient number, since it is larger than the sum of its proper divisors (1).

555021421 is an equidigital number, since it uses as much as digits as its factorization.

555021421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 555021421 is about 23558.8926097981. The cubic root of 555021421 is about 821.8071491472.

Adding to 555021421 its reverse (124120555), we get a palindrome (679141976).

The spelling of 555021421 in words is "five hundred fifty-five million, twenty-one thousand, four hundred twenty-one".