2091780 has 36 divisors (see below), whose sum is σ = 6345612. Its totient is φ = 557760.

The previous prime is 2091773. The next prime is 2091797. The reversal of 2091780 is 871902.

It can be written as a sum of positive squares in 2 ways, for example, as 412164 + 1679616 = 642^2 + 1296^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5631 + ... + 5990.

It is an arithmetic number, because the mean of its divisors is an integer number (176267).

2^2091780 is an apocalyptic number.

2091780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2091780 is an abundant number, since it is smaller than the sum of its proper divisors (4253832).

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

2091780 is a wasteful number, since it uses less digits than its factorization.

2091780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11636 (or 11631 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 2091780 is about 1446.2987243305. The cubic root of 2091780 is about 127.8906129261.

The spelling of 2091780 in words is "two million, ninety-one thousand, seven hundred eighty".