1286864640 has 216 divisors, whose sum is σ = 4715041968. Its totient is φ = 322928640.

The previous prime is 1286864639. The next prime is 1286864671. The reversal of 1286864640 is 464686821.

1286864640 is a `hidden beast` number, since 128 + 68 + 6 + 464 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 192555 + ... + 199125.

It is an arithmetic number, because the mean of its divisors is an integer number (21828898).

Almost surely, 2^1286864640 is an apocalyptic number.

1286864640 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 1286864640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2357520984).

1286864640 is an abundant number, since it is smaller than the sum of its proper divisors (3428177328).

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

1286864640 is a wasteful number, since it uses less digits than its factorization.

1286864640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6615 (or 6598 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 1286864640 is about 35872.8956177223. The cubic root of 1286864640 is about 1087.7045766541.

The spelling of 1286864640 in words is "one billion, two hundred eighty-six million, eight hundred sixty-four thousand, six hundred forty".