1239800161 has 2 divisors, whose sum is σ = 1239800162. Its totient is φ = 1239800160.

The previous prime is 1239800137. The next prime is 1239800203. The reversal of 1239800161 is 1610089321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 885419536 + 354380625 = 29756^2 + 18825^2 .

It is an emirp because it is prime and its reverse (1610089321) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1239800161 - 2¹⁵ = 1239767393 is a prime.

It is not a weakly prime, because it can be changed into another prime (1239800131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 619900080 + 619900081.

It is an arithmetic number, because the mean of its divisors is an integer number (619900081).

Almost surely, 2^1239800161 is an apocalyptic number.

It is an amenable number.

1239800161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1239800161 is an equidigital number, since it uses as much as digits as its factorization.

1239800161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 1239800161 is about 35210.7960858598. The cubic root of 1239800161 is about 1074.2793543276.

Adding to 1239800161 its reverse (1610089321), we get a palindrome (2849889482).

The spelling of 1239800161 in words is "one billion, two hundred thirty-nine million, eight hundred thousand, one hundred sixty-one".