121220001000 has 384 divisors, whose sum is σ = 468939144960. Its totient is φ = 27667008000.

The previous prime is 121220000963. The next prime is 121220001011. The reversal of 121220001000 is 100022121.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 74780190 + ... + 74781810.

It is an arithmetic number, because the mean of its divisors is an integer number (1221195690).

Almost surely, 2^121220001000 is an apocalyptic number.

121220001000 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 121220001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (234469572480).

121220001000 is an abundant number, since it is smaller than the sum of its proper divisors (347719143960).

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

121220001000 is a wasteful number, since it uses less digits than its factorization.

121220001000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2842 (or 2825 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 121220001000 its reverse (100022121), we get a palindrome (121320023121).

The spelling of 121220001000 in words is "one hundred twenty-one billion, two hundred twenty million, one thousand".