1261780 has 48 divisors (see below), whose sum is σ = 2991744. Its totient is φ = 443520.

The previous prime is 1261769. The next prime is 1261789. The reversal of 1261780 is 871621.

1261780 = 283² + 284² + ... + 297².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261789) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5875 + ... + 6085.

It is an arithmetic number, because the mean of its divisors is an integer number (62328).

2^1261780 is an apocalyptic number.

1261780 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 1261780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1495872).

1261780 is an abundant number, since it is smaller than the sum of its proper divisors (1729964).

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

1261780 is a wasteful number, since it uses less digits than its factorization.

1261780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 254 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 1261780 is about 1123.2898112242. The cubic root of 1261780 is about 108.0590669122.

The spelling of 1261780 in words is "one million, two hundred sixty-one thousand, seven hundred eighty".