127697981 has 2 divisors, whose sum is σ = 127697982. Its totient is φ = 127697980.

The previous prime is 127697963. The next prime is 127698019. The reversal of 127697981 is 189796721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126112900 + 1585081 = 11230^2 + 1259^2 .

It is a cyclic number.

It is not a de Polignac number, because 127697981 - 2¹⁴ = 127681597 is a prime.

It is a super-2 number, since 2×127697981² = 32613548702952722, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (127697681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63848990 + 63848991.

It is an arithmetic number, because the mean of its divisors is an integer number (63848991).

Almost surely, 2^127697981 is an apocalyptic number.

It is an amenable number.

127697981 is a deficient number, since it is larger than the sum of its proper divisors (1).

127697981 is an equidigital number, since it uses as much as digits as its factorization.

127697981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 381024, while the sum is 50.

The square root of 127697981 is about 11300.3531360750. The cubic root of 127697981 is about 503.5717326970.

The spelling of 127697981 in words is "one hundred twenty-seven million, six hundred ninety-seven thousand, nine hundred eighty-one".