121320909 has 42 divisors (see below), whose sum is σ = 192392046. Its totient is φ = 76457520.

The previous prime is 121320893. The next prime is 121320917. The reversal of 121320909 is 909023121.

It can be written as a sum of positive squares in only one way, i.e., 95004009 + 26316900 = 9747^2 + 5130^2 .

It is not a de Polignac number, because 121320909 - 2⁴ = 121320893 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121320709) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 262939 + ... + 263399.

It is an arithmetic number, because the mean of its divisors is an integer number (4580763).

Almost surely, 2^121320909 is an apocalyptic number.

121320909 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

121320909 is a deficient number, since it is larger than the sum of its proper divisors (71071137).

121320909 is an frugal number, since it uses more digits than its factorization.

121320909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517 (or 483 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 121320909 is about 11014.5771139885. The cubic root of 121320909 is about 495.0456156310.

It can be divided in two parts, 1213 and 20909, that added together give a palindrome (22122).

The spelling of 121320909 in words is "one hundred twenty-one million, three hundred twenty thousand, nine hundred nine".