122538721 has 2 divisors, whose sum is σ = 122538722. Its totient is φ = 122538720.

The previous prime is 122538719. The next prime is 122538727. The reversal of 122538721 is 127835221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68310225 + 54228496 = 8265^2 + 7364^2 .

It is a cyclic number.

It is not a de Polignac number, because 122538721 - 2¹ = 122538719 is a prime.

Together with 122538719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (122538727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61269360 + 61269361.

It is an arithmetic number, because the mean of its divisors is an integer number (61269361).

Almost surely, 2^122538721 is an apocalyptic number.

It is an amenable number.

122538721 is a deficient number, since it is larger than the sum of its proper divisors (1).

122538721 is an equidigital number, since it uses as much as digits as its factorization.

122538721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 31.

The square root of 122538721 is about 11069.7209088576. The cubic root of 122538721 is about 496.6965167311.

The spelling of 122538721 in words is "one hundred twenty-two million, five hundred thirty-eight thousand, seven hundred twenty-one".