127991077 has 4 divisors (see below), whose sum is σ = 128550220. Its totient is φ = 127431936.

The previous prime is 127991051. The next prime is 127991089. The reversal of 127991077 is 770199721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60980481 + 67010596 = 7809^2 + 8186^2 .

It is a cyclic number.

It is not a de Polignac number, because 127991077 - 2¹⁹ = 127466789 is a prime.

It is a house number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (127991047) 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, 279228 + ... + 279685.

It is an arithmetic number, because the mean of its divisors is an integer number (32137555).

Almost surely, 2^127991077 is an apocalyptic number.

It is an amenable number.

127991077 is a deficient number, since it is larger than the sum of its proper divisors (559143).

127991077 is an equidigital number, since it uses as much as digits as its factorization.

127991077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 559142.

The product of its (nonzero) digits is 55566, while the sum is 43.

The square root of 127991077 is about 11313.3141474990. The cubic root of 127991077 is about 503.9567089821.

The spelling of 127991077 in words is "one hundred twenty-seven million, nine hundred ninety-one thousand, seventy-seven".