2780020 has 24 divisors (see below), whose sum is σ = 5902344. Its totient is φ = 1099776.

The previous prime is 2779991. The next prime is 2780039. The reversal of 2780020 is 200872.

It can be written as a sum of positive squares in 4 ways, for example, as 583696 + 2196324 = 764^2 + 1482^2 .

It is a super-2 number, since 2×2780020² = 15457022400800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2780020.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1224 + ... + 2656.

It is an arithmetic number, because the mean of its divisors is an integer number (245931).

2^2780020 is an apocalyptic number.

2780020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2780020 is an abundant number, since it is smaller than the sum of its proper divisors (3122324).

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

2780020 is a wasteful number, since it uses less digits than its factorization.

2780020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539 (or 1537 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 2780020 is about 1667.3391976440. The cubic root of 2780020 is about 140.6099239805.

Adding to 2780020 its reverse (200872), we get a palindrome (2980892).

The spelling of 2780020 in words is "two million, seven hundred eighty thousand, twenty".