127665381 has 4 divisors (see below), whose sum is σ = 170220512. Its totient is φ = 85110252.

The previous prime is 127665379. The next prime is 127665383. The reversal of 127665381 is 183566721.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (127665379) and next prime (127665383).

It is not a de Polignac number, because 127665381 - 2¹ = 127665379 is a prime.

It is a super-2 number, since 2×127665381² = 32596899011750322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (127665383) 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 in 3 ways as a sum of consecutive naturals, for example, 21277561 + ... + 21277566.

It is an arithmetic number, because the mean of its divisors is an integer number (42555128).

Almost surely, 2^127665381 is an apocalyptic number.

It is an amenable number.

127665381 is a deficient number, since it is larger than the sum of its proper divisors (42555131).

127665381 is an equidigital number, since it uses as much as digits as its factorization.

127665381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42555130.

The product of its digits is 60480, while the sum is 39.

The square root of 127665381 is about 11298.9106112050. The cubic root of 127665381 is about 503.5288767971.

The spelling of 127665381 in words is "one hundred twenty-seven million, six hundred sixty-five thousand, three hundred eighty-one".