161901583 has 2 divisors, whose sum is σ = 161901584. Its totient is φ = 161901582.

The previous prime is 161901563. The next prime is 161901617. The reversal of 161901583 is 385109161.

161901583 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an a-pointer prime, because the next prime (161901617) can be obtained adding 161901583 to its sum of digits (34).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161901583 is a prime.

It is equal to p_9075049 and since 161901583 and 9075049 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161901533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80950791 + 80950792.

It is an arithmetic number, because the mean of its divisors is an integer number (80950792).

Almost surely, 2^161901583 is an apocalyptic number.

161901583 is a deficient number, since it is larger than the sum of its proper divisors (1).

161901583 is an equidigital number, since it uses as much as digits as its factorization.

161901583 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 161901583 is about 12724.0552890971. The cubic root of 161901583 is about 545.0257631678.

The spelling of 161901583 in words is "one hundred sixty-one million, nine hundred one thousand, five hundred eighty-three".