121651200000 has 864 divisors, whose sum is σ = 491486667840. Its totient is φ = 29491200000.

The previous prime is 121651199981. The next prime is 121651200001. The reversal of 121651200000 is 2156121.

121651200000 is a `hidden beast` number, since 12 + 1 + 651 + 2 + 0 + 0 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-2 number, since 2×121651200000² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121651200001) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11059199995 + ... + 11059200005.

It is an arithmetic number, because the mean of its divisors is an integer number (568850310).

Almost surely, 2^121651200000 is an apocalyptic number.

121651200000 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 121651200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (245743333920).

121651200000 is an abundant number, since it is smaller than the sum of its proper divisors (369835467840).

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

121651200000 is an frugal number, since it uses more digits than its factorization.

121651200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

Adding to 121651200000 its reverse (2156121), we get a palindrome (121653356121).

The spelling of 121651200000 in words is "one hundred twenty-one billion, six hundred fifty-one million, two hundred thousand".