121661010 has 96 divisors (see below), whose sum is σ = 338038272. Its totient is φ = 30251520.

The previous prime is 121660999. The next prime is 121661011. The reversal of 121661010 is 10166121.

121661010 is a `hidden beast` number, since 1 + 2 + 1 + 661 + 0 + 1 + 0 = 666.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (121661011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 200127 + ... + 200733.

It is an arithmetic number, because the mean of its divisors is an integer number (3521232).

Almost surely, 2^121661010 is an apocalyptic number.

121661010 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 121661010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169019136).

121661010 is an abundant number, since it is smaller than the sum of its proper divisors (216377262).

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

121661010 is a wasteful number, since it uses less digits than its factorization.

121661010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 768 (or 765 counting only the distinct ones).

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

The square root of 121661010 is about 11030.0049863996. The cubic root of 121661010 is about 495.5077740161.

It can be divided in two parts, 1216 and 61010, that added together give a palindrome (62226).

The spelling of 121661010 in words is "one hundred twenty-one million, six hundred sixty-one thousand, ten".