2145780 has 144 divisors (see below), whose sum is σ = 8072064. Its totient is φ = 449280.

The previous prime is 2145779. The next prime is 2145821. The reversal of 2145780 is 875412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 16315 + ... + 16445.

It is an arithmetic number, because the mean of its divisors is an integer number (56056).

2^2145780 is an apocalyptic number.

2145780 is a gapful number since it is divisible by the number (20) 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 2145780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4036032).

2145780 is an abundant number, since it is smaller than the sum of its proper divisors (5926284).

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

2145780 is a wasteful number, since it uses less digits than its factorization.

2145780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166 (or 161 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 2145780 is about 1464.8481149935. The cubic root of 2145780 is about 128.9817893890.

The spelling of 2145780 in words is "two million, one hundred forty-five thousand, seven hundred eighty".