5515121021549 has 2 divisors, whose sum is σ = 5515121021550. Its totient is φ = 5515121021548.

The previous prime is 5515121021483. The next prime is 5515121021551. The reversal of 5515121021549 is 9451201215155.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5506029399049 + 9091622500 = 2346493^2 + 95350^2 .

It is a cyclic number.

It is not a de Polignac number, because 5515121021549 - 2²⁸ = 5514852586093 is a prime.

Together with 5515121021551, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5515121021849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2757560510774 + 2757560510775.

It is an arithmetic number, because the mean of its divisors is an integer number (2757560510775).

Almost surely, 2^{5515121021549} is an apocalyptic number.

It is an amenable number.

5515121021549 is a deficient number, since it is larger than the sum of its proper divisors (1).

5515121021549 is an equidigital number, since it uses as much as digits as its factorization.

5515121021549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90000, while the sum is 41.

The spelling of 5515121021549 in words is "five trillion, five hundred fifteen billion, one hundred twenty-one million, twenty-one thousand, five hundred forty-nine".