121565283840 has 1920 divisors, whose sum is σ = 592477079040. Its totient is φ = 23224320000.

The previous prime is 121565283821. The next prime is 121565283871. The reversal of 121565283840 is 48382565121.

121565283840 is a `hidden beast` number, since 1 + 2 + 1 + 56 + 528 + 38 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 484323715 + ... + 484323965.

It is an arithmetic number, because the mean of its divisors is an integer number (308581812).

Almost surely, 2^121565283840 is an apocalyptic number.

121565283840 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 121565283840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (296238539520).

121565283840 is an abundant number, since it is smaller than the sum of its proper divisors (470911795200).

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

121565283840 is a wasteful number, since it uses less digits than its factorization.

121565283840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 45.

The spelling of 121565283840 in words is "one hundred twenty-one billion, five hundred sixty-five million, two hundred eighty-three thousand, eight hundred forty".