121856 has 44 divisors (see below), whose sum is σ = 294768. Its totient is φ = 49152.

The previous prime is 121853. The next prime is 121867. The reversal of 121856 is 658121.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

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 3 ways as a sum of consecutive naturals, for example, 7160 + ... + 7176.

2¹²¹⁸⁵⁶ is an apocalyptic number.

121856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147384).

121856 is an abundant number, since it is smaller than the sum of its proper divisors (172912).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

121856 is an equidigital number, since it uses as much as digits as its factorization.

121856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44 (or 26 counting only the distinct ones).

The product of its digits is 480, while the sum is 23.

The square root of 121856 is about 349.0787876683. The cubic root of 121856 is about 49.5772354779.

Adding to 121856 its reverse (658121), we get a palindrome (779977).

The spelling of 121856 in words is "one hundred twenty-one thousand, eight hundred fifty-six".