1291438512 has 540 divisors, whose sum is σ = 4928021640. Its totient is φ = 322672896.

The previous prime is 1291438483. The next prime is 1291438513. The reversal of 1291438512 is 2158341921.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

1291438512 is a `hidden beast` number, since 12 + 91 + 43 + 8 + 512 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (1291438513) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 67970439 + ... + 67970457.

It is an arithmetic number, because the mean of its divisors is an integer number (9125966).

Almost surely, 2^1291438512 is an apocalyptic number.

1291438512 is a gapful number since it is divisible by the number (12) 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 1291438512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2464010820).

1291438512 is an abundant number, since it is smaller than the sum of its proper divisors (3636583128).

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

1291438512 is a wasteful number, since it uses less digits than its factorization.

1291438512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 44 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 1291438512 is about 35936.5901554391. The cubic root of 1291438512 is about 1088.9917202962.

The spelling of 1291438512 in words is "one billion, two hundred ninety-one million, four hundred thirty-eight thousand, five hundred twelve".