161555003 has 2 divisors, whose sum is σ = 161555004. Its totient is φ = 161555002.

The previous prime is 161554997. The next prime is 161555021. The reversal of 161555003 is 300555161.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161555003 is a prime.

It is a super-2 number, since 2×161555003² = 52200037988660018, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161555503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80777501 + 80777502.

It is an arithmetic number, because the mean of its divisors is an integer number (80777502).

Almost surely, 2^161555003 is an apocalyptic number.

161555003 is a deficient number, since it is larger than the sum of its proper divisors (1).

161555003 is an equidigital number, since it uses as much as digits as its factorization.

161555003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 161555003 is about 12710.4289070039. The cubic root of 161555003 is about 544.6365761606.

The spelling of 161555003 in words is "one hundred sixty-one million, five hundred fifty-five thousand, three".