1261680 has 80 divisors (see below), whose sum is σ = 4475904. Its totient is φ = 288000.

The previous prime is 1261649. The next prime is 1261697. The reversal of 1261680 is 861621.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1261680.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1305 + ... + 2055.

2^1261680 is an apocalyptic number.

1261680 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 1261680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2237952).

1261680 is an abundant number, since it is smaller than the sum of its proper divisors (3214224).

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

1261680 is a wasteful number, since it uses less digits than its factorization.

1261680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774 (or 768 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 1261680 is about 1123.2452982319. The cubic root of 1261680 is about 108.0562121641.

The spelling of 1261680 in words is "one million, two hundred sixty-one thousand, six hundred eighty".