121989853440 has 1152 divisors, whose sum is σ = 540636364800. Its totient is φ = 25360957440.

The previous prime is 121989853423. The next prime is 121989853463. The reversal of 121989853440 is 44358989121.

It is a happy number.

121989853440 is a `hidden beast` number, since 1 + 2 + 19 + 8 + 98 + 534 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 248451595 + ... + 248452085.

It is an arithmetic number, because the mean of its divisors is an integer number (469302400).

Almost surely, 2^121989853440 is an apocalyptic number.

121989853440 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 121989853440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270318182400).

121989853440 is an abundant number, since it is smaller than the sum of its proper divisors (418646511360).

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

121989853440 is a wasteful number, since it uses less digits than its factorization.

121989853440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 600 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The spelling of 121989853440 in words is "one hundred twenty-one billion, nine hundred eighty-nine million, eight hundred fifty-three thousand, four hundred forty".