15551805551 has 2 divisors, whose sum is σ = 15551805552. Its totient is φ = 15551805550.

The previous prime is 15551805541. The next prime is 15551805671. The reversal of 15551805551 is 15550815551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 15551805551 - 2⁶ = 15551805487 is a prime.

It is a super-2 number, since 2×15551805551² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 15551805499 and 15551805508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15551805541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7775902775 + 7775902776.

It is an arithmetic number, because the mean of its divisors is an integer number (7775902776).

Almost surely, 2^15551805551 is an apocalyptic number.

15551805551 is a deficient number, since it is larger than the sum of its proper divisors (1).

15551805551 is an equidigital number, since it uses as much as digits as its factorization.

15551805551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 125000, while the sum is 41.

The spelling of 15551805551 in words is "fifteen billion, five hundred fifty-one million, eight hundred five thousand, five hundred fifty-one".