121221000 has 96 divisors (see below), whose sum is σ = 409757400. Its totient is φ = 32323200.

The previous prime is 121220993. The next prime is 121221013. The reversal of 121221000 is 122121.

It can be written as a sum of positive squares in 4 ways, for example, as 43322724 + 77898276 = 6582^2 + 8826^2 .

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

It is a nialpdrome in base 15.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2266 + ... + 15734.

Almost surely, 2^121221000 is an apocalyptic number.

121221000 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 121221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (204878700).

121221000 is an abundant number, since it is smaller than the sum of its proper divisors (288536400).

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

121221000 is a wasteful number, since it uses less digits than its factorization.

121221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13496 (or 13479 counting only the distinct ones).

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

The square root of 121221000 is about 11010.0408718587. The cubic root of 121221000 is about 494.9096866147.

Adding to 121221000 its reverse (122121), we get a palindrome (121343121).

The spelling of 121221000 in words is "one hundred twenty-one million, two hundred twenty-one thousand".