1271501920 has 144 divisors (see below), whose sum is σ = 3312051120. Its totient is φ = 460941312.

The previous prime is 1271501911. The next prime is 1271501923. The reversal of 1271501920 is 291051721.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1271501923) 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, 1594962 + ... + 1595758.

It is an arithmetic number, because the mean of its divisors is an integer number (23000355).

Almost surely, 2^1271501920 is an apocalyptic number.

1271501920 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 1271501920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1656025560).

1271501920 is an abundant number, since it is smaller than the sum of its proper divisors (2040549200).

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

1271501920 is a wasteful number, since it uses less digits than its factorization.

1271501920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 897 (or 876 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 28.

The square root of 1271501920 is about 35658.1255816960. The cubic root of 1271501920 is about 1083.3588616207.

The spelling of 1271501920 in words is "one billion, two hundred seventy-one million, five hundred one thousand, nine hundred twenty".