122105721 has 4 divisors (see below), whose sum is σ = 162807632. Its totient is φ = 81403812.

The previous prime is 122105701. The next prime is 122105743. The reversal of 122105721 is 127501221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 122105721 - 2¹³ = 122097529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (122105701) 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 3 ways as a sum of consecutive naturals, for example, 20350951 + ... + 20350956.

It is an arithmetic number, because the mean of its divisors is an integer number (40701908).

Almost surely, 2^122105721 is an apocalyptic number.

It is an amenable number.

122105721 is a deficient number, since it is larger than the sum of its proper divisors (40701911).

122105721 is an equidigital number, since it uses as much as digits as its factorization.

122105721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40701910.

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 122105721 is about 11050.1457456452. The cubic root of 122105721 is about 496.1107878282.

Adding to 122105721 its reverse (127501221), we get a palindrome (249606942).

The spelling of 122105721 in words is "one hundred twenty-two million, one hundred five thousand, seven hundred twenty-one".