161761603 has 4 divisors (see below), whose sum is σ = 163332208. Its totient is φ = 160191000.

The previous prime is 161761597. The next prime is 161761609. The reversal of 161761603 is 306167161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 306167161 = 17 ⋅18009833.

It is an interprime number because it is at equal distance from previous prime (161761597) and next prime (161761609).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161761603 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161761609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 785148 + ... + 785353.

It is an arithmetic number, because the mean of its divisors is an integer number (40833052).

Almost surely, 2^161761603 is an apocalyptic number.

161761603 is a deficient number, since it is larger than the sum of its proper divisors (1570605).

161761603 is a wasteful number, since it uses less digits than its factorization.

161761603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1570604.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 161761603 is about 12718.5534947965. The cubic root of 161761603 is about 544.8686415737.

The spelling of 161761603 in words is "one hundred sixty-one million, seven hundred sixty-one thousand, six hundred three".