127648721 has 2 divisors, whose sum is σ = 127648722. Its totient is φ = 127648720.

The previous prime is 127648687. The next prime is 127648739. The reversal of 127648721 is 127846721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71233600 + 56415121 = 8440^2 + 7511^2 .

It is a cyclic number.

It is not a de Polignac number, because 127648721 - 2¹⁰ = 127647697 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (127648021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63824360 + 63824361.

It is an arithmetic number, because the mean of its divisors is an integer number (63824361).

Almost surely, 2^127648721 is an apocalyptic number.

It is an amenable number.

127648721 is a deficient number, since it is larger than the sum of its proper divisors (1).

127648721 is an equidigital number, since it uses as much as digits as its factorization.

127648721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 37632, while the sum is 38.

The square root of 127648721 is about 11298.1733479355. The cubic root of 127648721 is about 503.5069727749.

The spelling of 127648721 in words is "one hundred twenty-seven million, six hundred forty-eight thousand, seven hundred twenty-one".