1271989799 has 4 divisors (see below), whose sum is σ = 1313021760. Its totient is φ = 1230957840.

The previous prime is 1271989783. The next prime is 1271989813. The reversal of 1271989799 is 9979891721.

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

It is a cyclic number.

It is not a de Polignac number, because 1271989799 - 2⁴ = 1271989783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1271988799) 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, 20515934 + ... + 20515995.

It is an arithmetic number, because the mean of its divisors is an integer number (328255440).

Almost surely, 2^1271989799 is an apocalyptic number.

1271989799 is a deficient number, since it is larger than the sum of its proper divisors (41031961).

1271989799 is an equidigital number, since it uses as much as digits as its factorization.

1271989799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41031960.

The product of its digits is 5143824, while the sum is 62.

The square root of 1271989799 is about 35664.9659890487. The cubic root of 1271989799 is about 1083.4974065551.

The spelling of 1271989799 in words is "one billion, two hundred seventy-one million, nine hundred eighty-nine thousand, seven hundred ninety-nine".