1309788481 has 3 divisors (see below), whose sum is σ = 1309824673. Its totient is φ = 1309752290.

The previous prime is 1309788463. The next prime is 1309788551. The reversal of 1309788481 is 1848879031.

The square root of 1309788481 is 36191.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1848879031 = 1361 ⋅1358471.

It is not a de Polignac number, because 1309788481 - 2⁷ = 1309788353 is a prime.

It is a super-2 number, since 2×1309788481² = 3431091729920574722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1309788461) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 18096 + ... + 54286.

Almost surely, 2^1309788481 is an apocalyptic number.

1309788481 is the 36191-st square number.

1309788481 is the 18096-th centered octagonal number.

It is an amenable number.

1309788481 is a deficient number, since it is larger than the sum of its proper divisors (36192).

1309788481 is an frugal number, since it uses more digits than its factorization.

1309788481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72382 (or 36191 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 49.

The cubic root of 1309788481 is about 1094.1252874191.

Multiplying 1309788481 by its sum of digits (49), we get a square (64179635569 = 253337²).

The spelling of 1309788481 in words is "one billion, three hundred nine million, seven hundred eighty-eight thousand, four hundred eighty-one".