121187840 has 40 divisors (see below), whose sum is σ = 290572920. Its totient is φ = 48474112.

The previous prime is 121187837. The next prime is 121187863. The reversal of 121187840 is 48781121.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 121187797 and 121187806.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 21110 + ... + 26229.

It is an arithmetic number, because the mean of its divisors is an integer number (7264323).

Almost surely, 2^121187840 is an apocalyptic number.

121187840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

121187840 is an abundant number, since it is smaller than the sum of its proper divisors (169385080).

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

121187840 is an frugal number, since it uses more digits than its factorization.

121187840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47362 (or 47346 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 32.

The square root of 121187840 is about 11008.5348707264. The cubic root of 121187840 is about 494.8645549905.

The spelling of 121187840 in words is "one hundred twenty-one million, one hundred eighty-seven thousand, eight hundred forty".