15555541 has 2 divisors, whose sum is σ = 15555542. Its totient is φ = 15555540.

The previous prime is 15555539. The next prime is 15555557. The reversal of 15555541 is 14555551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13140625 + 2414916 = 3625^2 + 1554^2 .

It is an emirp because it is prime and its reverse (14555551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15555541 - 2¹ = 15555539 is a prime.

Together with 15555539, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15555511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7777770 + 7777771.

It is an arithmetic number, because the mean of its divisors is an integer number (7777771).

Almost surely, 2^15555541 is an apocalyptic number.

It is an amenable number.

15555541 is a deficient number, since it is larger than the sum of its proper divisors (1).

15555541 is an equidigital number, since it uses as much as digits as its factorization.

15555541 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12500, while the sum is 31.

The square root of 15555541 is about 3944.0513434792. The cubic root of 15555541 is about 249.6290017134.

It can be divided in two parts, 155 and 55541, that added together give a square (55696 = 236²).

The spelling of 15555541 in words is "fifteen million, five hundred fifty-five thousand, five hundred forty-one".