15555555397 has 2 divisors, whose sum is σ = 15555555398. Its totient is φ = 15555555396.

The previous prime is 15555555391. The next prime is 15555555401. The reversal of 15555555397 is 79355555551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13105899361 + 2449656036 = 114481^2 + 49494^2 .

It is a cyclic number.

It is not a de Polignac number, because 15555555397 - 2⁷ = 15555555269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15555555391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7777777698 + 7777777699.

It is an arithmetic number, because the mean of its divisors is an integer number (7777777699).

Almost surely, 2^15555555397 is an apocalyptic number.

It is an amenable number.

15555555397 is a deficient number, since it is larger than the sum of its proper divisors (1).

15555555397 is an equidigital number, since it uses as much as digits as its factorization.

15555555397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14765625, while the sum is 55.

The spelling of 15555555397 in words is "fifteen billion, five hundred fifty-five million, five hundred fifty-five thousand, three hundred ninety-seven".