127664639 has 4 divisors (see below), whose sum is σ = 127901160. Its totient is φ = 127428120.

The previous prime is 127664633. The next prime is 127664657. The reversal of 127664639 is 936466721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936466721 = 337 ⋅2778833.

It is a cyclic number.

It is not a de Polignac number, because 127664639 - 2⁴ = 127664623 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 127664639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (127664633) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117449 + ... + 118530.

It is an arithmetic number, because the mean of its divisors is an integer number (31975290).

Almost surely, 2^127664639 is an apocalyptic number.

127664639 is a deficient number, since it is larger than the sum of its proper divisors (236521).

127664639 is an equidigital number, since it uses as much as digits as its factorization.

127664639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236520.

The product of its digits is 326592, while the sum is 44.

The square root of 127664639 is about 11298.8777761333. The cubic root of 127664639 is about 503.5279012804.

The spelling of 127664639 in words is "one hundred twenty-seven million, six hundred sixty-four thousand, six hundred thirty-nine".