121851 has 8 divisors (see below), whose sum is σ = 180560. Its totient is φ = 81216.

The previous prime is 121843. The next prime is 121853. The reversal of 121851 is 158121.

It is not a de Polignac number, because 121851 - 2³ = 121843 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121853) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2230 + ... + 2283.

It is an arithmetic number, because the mean of its divisors is an integer number (22570).

2¹²¹⁸⁵¹ is an apocalyptic number.

121851 is a deficient number, since it is larger than the sum of its proper divisors (58709).

121851 is an equidigital number, since it uses as much as digits as its factorization.

121851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4522 (or 4516 counting only the distinct ones).

The product of its digits is 80, while the sum is 18.

The square root of 121851 is about 349.0716258879. The cubic root of 121851 is about 49.5765573837.

Subtracting from 121851 its product of digits (80), we obtain a triangular number (121771 = T₄₉₃).

Adding to 121851 its reverse (158121), we get a palindrome (279972).

The spelling of 121851 in words is "one hundred twenty-one thousand, eight hundred fifty-one".