5515105256721 has 6 divisors (see below), whose sum is σ = 7966263148610. Its totient is φ = 3676736837808.

The previous prime is 5515105256693. The next prime is 5515105256723. The reversal of 5515105256721 is 1276525015155.

5515105256721 is a `hidden beast` number, since 5 + 5 + 1 + 5 + 10 + 52 + 567 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4315009107600 + 1200096149121 = 2077260^2 + 1095489^2 .

It is not a de Polignac number, because 5515105256721 - 2¹⁸ = 5515104994577 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5515105256723) 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 in 5 ways as a sum of consecutive naturals, for example, 306394736476 + ... + 306394736493.

Almost surely, 2^{5515105256721} is an apocalyptic number.

It is an amenable number.

5515105256721 is a deficient number, since it is larger than the sum of its proper divisors (2451157891889).

5515105256721 is a wasteful number, since it uses less digits than its factorization.

5515105256721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612789472975 (or 612789472972 counting only the distinct ones).

The product of its (nonzero) digits is 525000, while the sum is 45.

The spelling of 5515105256721 in words is "five trillion, five hundred fifteen billion, one hundred five million, two hundred fifty-six thousand, seven hundred twenty-one".