121838640 has 320 divisors, whose sum is σ = 497111040. Its totient is φ = 23915520.

The previous prime is 121838581. The next prime is 121838671. The reversal of 121838640 is 46838121.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 350947 + ... + 351293.

It is an arithmetic number, because the mean of its divisors is an integer number (1553472).

Almost surely, 2^121838640 is an apocalyptic number.

121838640 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 121838640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (248555520).

121838640 is an abundant number, since it is smaller than the sum of its proper divisors (375272400).

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

121838640 is a wasteful number, since it uses less digits than its factorization.

121838640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400 (or 394 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 33.

The square root of 121838640 is about 11038.0541763483. The cubic root of 121838640 is about 495.7488105500.

The spelling of 121838640 in words is "one hundred twenty-one million, eight hundred thirty-eight thousand, six hundred forty".