121500161 has 4 divisors (see below), whose sum is σ = 122035632. Its totient is φ = 120964692.

The previous prime is 121500157. The next prime is 121500167. The reversal of 121500161 is 161005121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 161005121 = 1009 ⋅159569.

It is a cyclic number.

It is not a de Polignac number, because 121500161 - 2² = 121500157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121500167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267395 + ... + 267848.

It is an arithmetic number, because the mean of its divisors is an integer number (30508908).

Almost surely, 2^121500161 is an apocalyptic number.

It is an amenable number.

121500161 is a deficient number, since it is larger than the sum of its proper divisors (535471).

121500161 is an equidigital number, since it uses as much as digits as its factorization.

121500161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535470.

The product of its (nonzero) digits is 60, while the sum is 17.

The square root of 121500161 is about 11022.7111456302. The cubic root of 121500161 is about 495.2893061038.

Adding to 121500161 its reverse (161005121), we get a palindrome (282505282).

The spelling of 121500161 in words is "one hundred twenty-one million, five hundred thousand, one hundred sixty-one".