127929721 has 2 divisors, whose sum is σ = 127929722. Its totient is φ = 127929720.

The previous prime is 127929719. The next prime is 127929727.

127929721 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., 102819600 + 25110121 = 10140^2 + 5011^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 127929721 - 2¹ = 127929719 is a prime.

Together with 127929719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (127929727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63964860 + 63964861.

It is an arithmetic number, because the mean of its divisors is an integer number (63964861).

Almost surely, 2^127929721 is an apocalyptic number.

It is an amenable number.

127929721 is a deficient number, since it is larger than the sum of its proper divisors (1).

127929721 is an equidigital number, since it uses as much as digits as its factorization.

127929721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31752, while the sum is 40.

The square root of 127929721 is about 11310.6021501952. The cubic root of 127929721 is about 503.8761676643.

The spelling of 127929721 in words is "one hundred twenty-seven million, nine hundred twenty-nine thousand, seven hundred twenty-one".