121621500 has 576 divisors, whose sum is σ = 534223872. Its totient is φ = 23328000.

The previous prime is 121621469. The next prime is 121621517. The reversal of 121621500 is 5126121.

121621500 is a `hidden beast` number, since 1 + 2 + 162 + 1 + 500 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 9355494 + ... + 9355506.

It is an arithmetic number, because the mean of its divisors is an integer number (927472).

Almost surely, 2^121621500 is an apocalyptic number.

121621500 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 121621500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (267111936).

121621500 is an abundant number, since it is smaller than the sum of its proper divisors (412602372).

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

121621500 is a wasteful number, since it uses less digits than its factorization.

121621500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65 (or 41 counting only the distinct ones).

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

The square root of 121621500 is about 11028.2138172961. The cubic root of 121621500 is about 495.4541286951.

Adding to 121621500 its reverse (5126121), we get a palindrome (126747621).

The spelling of 121621500 in words is "one hundred twenty-one million, six hundred twenty-one thousand, five hundred".