1271988720 has 120 divisors (see below), whose sum is σ = 4419136800. Its totient is φ = 327495168.

The previous prime is 1271988703. The next prime is 1271988727. The reversal of 1271988720 is 278891721.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1271988727) 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 23 ways as a sum of consecutive naturals, for example, 9580 + ... + 51339.

It is an arithmetic number, because the mean of its divisors is an integer number (36826140).

Almost surely, 2^1271988720 is an apocalyptic number.

1271988720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1271988720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2209568400).

1271988720 is an abundant number, since it is smaller than the sum of its proper divisors (3147148080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1271988720 is a wasteful number, since it uses less digits than its factorization.

1271988720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60967 (or 60958 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 45.

The square root of 1271988720 is about 35664.9508621560. The cubic root of 1271988720 is about 1083.4971001863.

The spelling of 1271988720 in words is "one billion, two hundred seventy-one million, nine hundred eighty-eight thousand, seven hundred twenty".