127749421 has 2 divisors, whose sum is σ = 127749422. Its totient is φ = 127749420.

The previous prime is 127749409. The next prime is 127749449. The reversal of 127749421 is 124947721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 113955625 + 13793796 = 10675^2 + 3714^2 .

It is an emirp because it is prime and its reverse (124947721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 127749421 - 2¹⁵ = 127716653 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (127749121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63874710 + 63874711.

It is an arithmetic number, because the mean of its divisors is an integer number (63874711).

Almost surely, 2^127749421 is an apocalyptic number.

It is an amenable number.

127749421 is a deficient number, since it is larger than the sum of its proper divisors (1).

127749421 is an equidigital number, since it uses as much as digits as its factorization.

127749421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 37.

The square root of 127749421 is about 11302.6289419763. The cubic root of 127749421 is about 503.6393407940.

The spelling of 127749421 in words is "one hundred twenty-seven million, seven hundred forty-nine thousand, four hundred twenty-one".