1311761920 has 160 divisors (see below), whose sum is σ = 3648623616. Its totient is φ = 442982400.

The previous prime is 1311761911. The next prime is 1311761977. The reversal of 1311761920 is 291671131.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1271805 + ... + 1272835.

Almost surely, 2^1311761920 is an apocalyptic number.

1311761920 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 1311761920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1824311808).

1311761920 is an abundant number, since it is smaller than the sum of its proper divisors (2336861696).

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

1311761920 is an equidigital number, since it uses as much as digits as its factorization.

1311761920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132 (or 1116 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 31.

The square root of 1311761920 is about 36218.2539612279. The cubic root of 1311761920 is about 1094.6745124899.

The spelling of 1311761920 in words is "one billion, three hundred eleven million, seven hundred sixty-one thousand, nine hundred twenty".