3551551021 has 2 divisors, whose sum is σ = 3551551022. Its totient is φ = 3551551020.

The previous prime is 3551551019. The next prime is 3551551043. The reversal of 3551551021 is 1201551553.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3247746121 + 303804900 = 56989^2 + 17430^2 .

It is an emirp because it is prime and its reverse (1201551553) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3551551021 - 2¹ = 3551551019 is a prime.

It is a super-2 number, since 2×3551551021² = 25227029309532284882, which contains 22 as substring.

Together with 3551551019, 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 (3551551051) 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, 1775775510 + 1775775511.

It is an arithmetic number, because the mean of its divisors is an integer number (1775775511).

Almost surely, 2^3551551021 is an apocalyptic number.

It is an amenable number.

3551551021 is a deficient number, since it is larger than the sum of its proper divisors (1).

3551551021 is an equidigital number, since it uses as much as digits as its factorization.

3551551021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3750, while the sum is 28.

The square root of 3551551021 is about 59594.8908967875. The cubic root of 3551551021 is about 1525.7124355147.

The spelling of 3551551021 in words is "three billion, five hundred fifty-one million, five hundred fifty-one thousand, twenty-one".