551405321 has 2 divisors, whose sum is σ = 551405322. Its totient is φ = 551405320.

The previous prime is 551405311. The next prime is 551405329. The reversal of 551405321 is 123504155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 530657296 + 20748025 = 23036^2 + 4555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-551405321 is a prime.

It is a super-2 number, since 2×551405321² = 608095656054226082, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (551405329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 275702660 + 275702661.

It is an arithmetic number, because the mean of its divisors is an integer number (275702661).

Almost surely, 2^551405321 is an apocalyptic number.

It is an amenable number.

551405321 is a deficient number, since it is larger than the sum of its proper divisors (1).

551405321 is an equidigital number, since it uses as much as digits as its factorization.

551405321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 551405321 is about 23482.0212290169. The cubic root of 551405321 is about 820.0185009706.

Adding to 551405321 its reverse (123504155), we get a palindrome (674909476).

The spelling of 551405321 in words is "five hundred fifty-one million, four hundred five thousand, three hundred twenty-one".