1291606812 has 72 divisors (see below), whose sum is σ = 3380360256. Its totient is φ = 415563264.

The previous prime is 1291606793. The next prime is 1291606829. The reversal of 1291606812 is 2186061921.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 118288 + ... + 128744.

It is an arithmetic number, because the mean of its divisors is an integer number (46949448).

Almost surely, 2^1291606812 is an apocalyptic number.

1291606812 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 1291606812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1690180128).

1291606812 is an abundant number, since it is smaller than the sum of its proper divisors (2088753444).

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

1291606812 is a wasteful number, since it uses less digits than its factorization.

1291606812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10587 (or 10582 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 1291606812 is about 35938.9317036553. The cubic root of 1291606812 is about 1089.0390239667.

The spelling of 1291606812 in words is "one billion, two hundred ninety-one million, six hundred six thousand, eight hundred twelve".