2780987 has 4 divisors (see below), whose sum is σ = 3033816. Its totient is φ = 2528160.

The previous prime is 2780971. The next prime is 2780993. The reversal of 2780987 is 7890872.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2780987 - 2⁴ = 2780971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2780887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126398 + ... + 126419.

It is an arithmetic number, because the mean of its divisors is an integer number (758454).

2^2780987 is an apocalyptic number.

2780987 is a deficient number, since it is larger than the sum of its proper divisors (252829).

2780987 is a wasteful number, since it uses less digits than its factorization.

2780987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252828.

The product of its (nonzero) digits is 56448, while the sum is 41.

The square root of 2780987 is about 1667.6291554180. The cubic root of 2780987 is about 140.6262253062.

The spelling of 2780987 in words is "two million, seven hundred eighty thousand, nine hundred eighty-seven".