121616640 has 432 divisors, whose sum is σ = 482122368. Its totient is φ = 29196288.

The previous prime is 121616639. The next prime is 121616653. The reversal of 121616640 is 46616121.

121616640 is a `hidden beast` number, since 1 + 2 + 1 + 6 + 16 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (432).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5287669 + ... + 5287691.

It is an arithmetic number, because the mean of its divisors is an integer number (1116024).

Almost surely, 2^121616640 is an apocalyptic number.

121616640 is a gapful number since it is divisible by the number (10) 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 121616640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241061184).

121616640 is an abundant number, since it is smaller than the sum of its proper divisors (360505728).

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

121616640 is an equidigital number, since it uses as much as digits as its factorization.

121616640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76 (or 50 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 121616640 is about 11027.9934711624. The cubic root of 121616640 is about 495.4475291516.

The spelling of 121616640 in words is "one hundred twenty-one million, six hundred sixteen thousand, six hundred forty".