121785 has 16 divisors (see below), whose sum is σ = 203904. Its totient is φ = 61952.

The previous prime is 121763. The next prime is 121787. The reversal of 121785 is 587121.

It is a cyclic number.

It is not a de Polignac number, because 121785 - 2⁶ = 121721 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (121787) 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, 169 + ... + 521.

It is an arithmetic number, because the mean of its divisors is an integer number (12744).

2¹²¹⁷⁸⁵ is an apocalyptic number.

121785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

121785 is a deficient number, since it is larger than the sum of its proper divisors (82119).

121785 is a wasteful number, since it uses less digits than its factorization.

121785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384.

The product of its digits is 560, while the sum is 24.

The square root of 121785 is about 348.9770766111. The cubic root of 121785 is about 49.5676048002.

The spelling of 121785 in words is "one hundred twenty-one thousand, seven hundred eighty-five".