121056721 has 2 divisors, whose sum is σ = 121056722. Its totient is φ = 121056720.

The previous prime is 121056673. The next prime is 121056743. The reversal of 121056721 is 127650121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64641600 + 56415121 = 8040^2 + 7511^2 .

It is an emirp because it is prime and its reverse (127650121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121056721 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (121056791) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60528360 + 60528361.

It is an arithmetic number, because the mean of its divisors is an integer number (60528361).

Almost surely, 2^121056721 is an apocalyptic number.

It is an amenable number.

121056721 is a deficient number, since it is larger than the sum of its proper divisors (1).

121056721 is an equidigital number, since it uses as much as digits as its factorization.

121056721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 121056721 is about 11002.5779251955. The cubic root of 121056721 is about 494.6860179337.

The spelling of 121056721 in words is "one hundred twenty-one million, fifty-six thousand, seven hundred twenty-one".