127779971 has 4 divisors (see below), whose sum is σ = 139396344. Its totient is φ = 116163600.

The previous prime is 127779941. The next prime is 127779991. The reversal of 127779971 is 179977721.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-127779971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127779901) 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, 5808170 + ... + 5808191.

It is an arithmetic number, because the mean of its divisors is an integer number (34849086).

Almost surely, 2^127779971 is an apocalyptic number.

127779971 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

127779971 is a deficient number, since it is larger than the sum of its proper divisors (11616373).

127779971 is a wasteful number, since it uses less digits than its factorization.

127779971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11616372.

The product of its digits is 388962, while the sum is 50.

The square root of 127779971 is about 11303.9803166849. The cubic root of 127779971 is about 503.6794843694.

The spelling of 127779971 in words is "one hundred twenty-seven million, seven hundred seventy-nine thousand, nine hundred seventy-one".