155661306503 has 2 divisors, whose sum is σ = 155661306504. Its totient is φ = 155661306502.

The previous prime is 155661306491. The next prime is 155661306509. The reversal of 155661306503 is 305603166551.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 155661306503 - 2⁶ = 155661306439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155661306509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77830653251 + 77830653252.

It is an arithmetic number, because the mean of its divisors is an integer number (77830653252).

Almost surely, 2^155661306503 is an apocalyptic number.

155661306503 is a deficient number, since it is larger than the sum of its proper divisors (1).

155661306503 is an equidigital number, since it uses as much as digits as its factorization.

155661306503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 243000, while the sum is 41.

The spelling of 155661306503 in words is "one hundred fifty-five billion, six hundred sixty-one million, three hundred six thousand, five hundred three".