121661100 has 108 divisors (see below), whose sum is σ = 416041080. Its totient is φ = 29491200.

The previous prime is 121661077. The next prime is 121661107. The reversal of 121661100 is 1166121.

121661100 is a `hidden beast` number, since 1 + 2 + 1 + 661 + 1 + 0 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (121661107) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3756 + ... + 16044.

Almost surely, 2^121661100 is an apocalyptic number.

121661100 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 121661100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (208020540).

121661100 is an abundant number, since it is smaller than the sum of its proper divisors (294379980).

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

121661100 is a wasteful number, since it uses less digits than its factorization.

121661100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12320 (or 12310 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 121661100 is about 11030.0090661794. The cubic root of 121661100 is about 495.5078962018.

The spelling of 121661100 in words is "one hundred twenty-one million, six hundred sixty-one thousand, one hundred".