15557115109 has 2 divisors, whose sum is σ = 15557115110. Its totient is φ = 15557115108.

The previous prime is 15557115037. The next prime is 15557115131. The reversal of 15557115109 is 90151175551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15264602500 + 292512609 = 123550^2 + 17103^2 .

It is a cyclic number.

It is not a de Polignac number, because 15557115109 - 2⁷ = 15557114981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15557115139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7778557554 + 7778557555.

It is an arithmetic number, because the mean of its divisors is an integer number (7778557555).

Almost surely, 2^15557115109 is an apocalyptic number.

It is an amenable number.

15557115109 is a deficient number, since it is larger than the sum of its proper divisors (1).

15557115109 is an equidigital number, since it uses as much as digits as its factorization.

15557115109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 39375, while the sum is 40.

The spelling of 15557115109 in words is "fifteen billion, five hundred fifty-seven million, one hundred fifteen thousand, one hundred nine".