1306640 has 20 divisors (see below), whose sum is σ = 3038124. Its totient is φ = 522624.

The previous prime is 1306633. The next prime is 1306661. The reversal of 1306640 is 466031.

It can be written as a sum of positive squares in 2 ways, for example, as 258064 + 1048576 = 508^2 + 1024^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8087 + ... + 8246.

2^1306640 is an apocalyptic number.

1306640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1306640 is an abundant number, since it is smaller than the sum of its proper divisors (1731484).

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

1306640 is a wasteful number, since it uses less digits than its factorization.

1306640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16346 (or 16340 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 20.

The square root of 1306640 is about 1143.0835490024. The cubic root of 1306640 is about 109.3247894705.

The spelling of 1306640 in words is "one million, three hundred six thousand, six hundred forty".