1291525536 has 144 divisors (see below), whose sum is σ = 3958948224. Its totient is φ = 367589376.

The previous prime is 1291525531. The next prime is 1291525553. The reversal of 1291525536 is 6355251921.

It is a junction number, because it is equal to n+sod(n) for n = 1291525494 and 1291525503.

It is not an unprimeable number, because it can be changed into a prime (1291525531) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2177656 + ... + 2178248.

It is an arithmetic number, because the mean of its divisors is an integer number (27492696).

Almost surely, 2^1291525536 is an apocalyptic number.

1291525536 is a gapful number since it is divisible by the number (16) 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 1291525536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1979474112).

1291525536 is an abundant number, since it is smaller than the sum of its proper divisors (2667422688).

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

1291525536 is a wasteful number, since it uses less digits than its factorization.

1291525536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1083 (or 1068 counting only the distinct ones).

The product of its digits is 81000, while the sum is 39.

The square root of 1291525536 is about 35937.8009343922. The cubic root of 1291525536 is about 1089.0161804327.

The spelling of 1291525536 in words is "one billion, two hundred ninety-one million, five hundred twenty-five thousand, five hundred thirty-six".