121642129 has 16 divisors (see below), whose sum is σ = 141978240. Its totient is φ = 102061440.

The previous prime is 121642111. The next prime is 121642139. The reversal of 121642129 is 921246121.

It is a cyclic number.

It is not a de Polignac number, because 121642129 - 2¹¹ = 121640081 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121642097 and 121642106.

It is not an unprimeable number, because it can be changed into a prime (121642139) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 128799 + ... + 129739.

It is an arithmetic number, because the mean of its divisors is an integer number (8873640).

Almost surely, 2^121642129 is an apocalyptic number.

It is an amenable number.

121642129 is a deficient number, since it is larger than the sum of its proper divisors (20336111).

121642129 is an equidigital number, since it uses as much as digits as its factorization.

121642129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1320.

The product of its digits is 1728, while the sum is 28.

The square root of 121642129 is about 11029.1490605577. The cubic root of 121642129 is about 495.4821394920.

It can be divided in two parts, 121642 and 129, that added together give a triangular number (121771 = T₄₉₃).

The spelling of 121642129 in words is "one hundred twenty-one million, six hundred forty-two thousand, one hundred twenty-nine".