It is a congruent number.
It is an unprimeable number.
22145780 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).
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 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".