127212721 has 2 divisors, whose sum is σ = 127212722. Its totient is φ = 127212720.

The previous prime is 127212719. The next prime is 127212737.

127212721 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122213025 + 4999696 = 11055^2 + 2236^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 127212721 - 2¹ = 127212719 is a prime.

Together with 127212719, it forms a pair of twin primes.

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 (127212121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63606360 + 63606361.

It is an arithmetic number, because the mean of its divisors is an integer number (63606361).

Almost surely, 2^127212721 is an apocalyptic number.

It is an amenable number.

127212721 is a deficient number, since it is larger than the sum of its proper divisors (1).

127212721 is an equidigital number, since it uses as much as digits as its factorization.

127212721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 784, while the sum is 25.

The square root of 127212721 is about 11278.8616890181. The cubic root of 127212721 is about 502.9330553954.

The spelling of 127212721 in words is "one hundred twenty-seven million, two hundred twelve thousand, seven hundred twenty-one".