127709921 has 2 divisors, whose sum is σ = 127709922. Its totient is φ = 127709920.

The previous prime is 127709891. The next prime is 127709941. The reversal of 127709921 is 129907721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 68973025 + 58736896 = 8305^2 + 7664^2 .

It is a cyclic number.

It is not a de Polignac number, because 127709921 - 2¹⁰ = 127708897 is a prime.

It is not a weakly prime, because it can be changed into another prime (127709941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63854960 + 63854961.

It is an arithmetic number, because the mean of its divisors is an integer number (63854961).

Almost surely, 2^127709921 is an apocalyptic number.

It is an amenable number.

127709921 is a deficient number, since it is larger than the sum of its proper divisors (1).

127709921 is an equidigital number, since it uses as much as digits as its factorization.

127709921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15876, while the sum is 38.

The square root of 127709921 is about 11300.8814258004. The cubic root of 127709921 is about 503.5874271740.

The spelling of 127709921 in words is "one hundred twenty-seven million, seven hundred nine thousand, nine hundred twenty-one".