1286655640 has 32 divisors (see below), whose sum is σ = 2896170480. Its totient is φ = 514449792.

The previous prime is 1286655619. The next prime is 1286655653. The reversal of 1286655640 is 465566821.

1286655640 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122434 + ... + 132526.

Almost surely, 2^1286655640 is an apocalyptic number.

1286655640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1286655640 is an abundant number, since it is smaller than the sum of its proper divisors (1609514840).

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

1286655640 is a wasteful number, since it uses less digits than its factorization.

1286655640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13291 (or 13287 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 43.

The square root of 1286655640 is about 35869.9824365722. The cubic root of 1286655640 is about 1087.6456886774.

The spelling of 1286655640 in words is "one billion, two hundred eighty-six million, six hundred fifty-five thousand, six hundred forty".