121351644 has 72 divisors (see below), whose sum is σ = 328844880. Its totient is φ = 37596672.

The previous prime is 121351621. The next prime is 121351649. The reversal of 121351644 is 446153121.

It is a happy number.

121351644 is a `hidden beast` number, since 1 + 2 + 13 + 5 + 1 + 644 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121351649) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49602 + ... + 51990.

It is an arithmetic number, because the mean of its divisors is an integer number (4567290).

Almost surely, 2^121351644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 121351644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (164422440).

121351644 is an abundant number, since it is smaller than the sum of its proper divisors (207493236).

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

121351644 is a wasteful number, since it uses less digits than its factorization.

121351644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2499 (or 2494 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 121351644 is about 11015.9722221872. The cubic root of 121351644 is about 495.0874164561.

The spelling of 121351644 in words is "one hundred twenty-one million, three hundred fifty-one thousand, six hundred forty-four".