127651661 has 2 divisors, whose sum is σ = 127651662. Its totient is φ = 127651660.

The previous prime is 127651651. The next prime is 127651663. The reversal of 127651661 is 166156721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90136036 + 37515625 = 9494^2 + 6125^2 .

It is an emirp because it is prime and its reverse (166156721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 127651661 - 2²² = 123457357 is a prime.

Together with 127651663, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (127651663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63825830 + 63825831.

It is an arithmetic number, because the mean of its divisors is an integer number (63825831).

Almost surely, 2^127651661 is an apocalyptic number.

It is an amenable number.

127651661 is a deficient number, since it is larger than the sum of its proper divisors (1).

127651661 is an equidigital number, since it uses as much as digits as its factorization.

127651661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 35.

The square root of 127651661 is about 11298.3034567142. The cubic root of 127651661 is about 503.5108383291.

The spelling of 127651661 in words is "one hundred twenty-seven million, six hundred fifty-one thousand, six hundred sixty-one".