161501213 has 2 divisors, whose sum is σ = 161501214. Its totient is φ = 161501212.

The previous prime is 161501183. The next prime is 161501233. The reversal of 161501213 is 312105161.

It is an a-pointer prime, because the next prime (161501233) can be obtained adding 161501213 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 145033849 + 16467364 = 12043^2 + 4058^2 .

It is a cyclic number.

It is not a de Polignac number, because 161501213 - 2⁶ = 161501149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161501233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80750606 + 80750607.

It is an arithmetic number, because the mean of its divisors is an integer number (80750607).

Almost surely, 2^161501213 is an apocalyptic number.

It is an amenable number.

161501213 is a deficient number, since it is larger than the sum of its proper divisors (1).

161501213 is an equidigital number, since it uses as much as digits as its factorization.

161501213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 161501213 is about 12708.3127518959. The cubic root of 161501213 is about 544.5761235740.

Adding to 161501213 its reverse (312105161), we get a palindrome (473606374).

The spelling of 161501213 in words is "one hundred sixty-one million, five hundred one thousand, two hundred thirteen".