15551661005511 has 4 divisors (see below), whose sum is σ = 20735548007352. Its totient is φ = 10367774003672.

The previous prime is 15551661005509. The next prime is 15551661005527. The reversal of 15551661005511 is 11550016615551.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 15551661005511 - 2¹ = 15551661005509 is a prime.

It is a super-2 number, since 2×15551661005511² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15551661005501) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2591943500916 + ... + 2591943500921.

It is an arithmetic number, because the mean of its divisors is an integer number (5183887001838).

Almost surely, 2^{15551661005511} is an apocalyptic number.

15551661005511 is a deficient number, since it is larger than the sum of its proper divisors (5183887001841).

15551661005511 is an equidigital number, since it uses as much as digits as its factorization.

15551661005511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5183887001840.

The product of its (nonzero) digits is 112500, while the sum is 42.

The spelling of 15551661005511 in words is "fifteen trillion, five hundred fifty-one billion, six hundred sixty-one million, five thousand, five hundred eleven".