121989156 has 12 divisors (see below), whose sum is σ = 284641392. Its totient is φ = 40663048.

The previous prime is 121989149. The next prime is 121989163. The reversal of 121989156 is 651989121.

It is an interprime number because it is at equal distance from previous prime (121989149) and next prime (121989163).

It is a tau number, because it is divible by the number of its divisors (12).

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, 5082870 + ... + 5082893.

It is an arithmetic number, because the mean of its divisors is an integer number (23720116).

Almost surely, 2^121989156 is an apocalyptic number.

It is an amenable number.

121989156 is an abundant number, since it is smaller than the sum of its proper divisors (162652236).

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

121989156 is a wasteful number, since it uses less digits than its factorization.

121989156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10165770 (or 10165768 counting only the distinct ones).

The product of its digits is 38880, while the sum is 42.

The square root of 121989156 is about 11044.8701214636. The cubic root of 121989156 is about 495.9528712158.

The spelling of 121989156 in words is "one hundred twenty-one million, nine hundred eighty-nine thousand, one hundred fifty-six".