121640256 has 84 divisors (see below), whose sum is σ = 350593152. Its totient is φ = 40322304.

The previous prime is 121640243. The next prime is 121640257. The reversal of 121640256 is 652046121.

121640256 is a `hidden beast` number, since 12 + 1 + 640 + 2 + 5 + 6 = 666.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121640257) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 127975 + ... + 128921.

It is an arithmetic number, because the mean of its divisors is an integer number (4173728).

Almost surely, 2^121640256 is an apocalyptic number.

121640256 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 121640256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (175296576).

121640256 is an abundant number, since it is smaller than the sum of its proper divisors (228952896).

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

121640256 is a wasteful number, since it uses less digits than its factorization.

121640256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1188 (or 1175 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 121640256 is about 11029.0641488750. The cubic root of 121640256 is about 495.4795963960.

Adding to 121640256 its reverse (652046121), we get a palindrome (773686377).

The spelling of 121640256 in words is "one hundred twenty-one million, six hundred forty thousand, two hundred fifty-six".