2787121 has 2 divisors, whose sum is σ = 2787122. Its totient is φ = 2787120.

The previous prime is 2787119. The next prime is 2787143. The reversal of 2787121 is 1217872.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2768896 + 18225 = 1664^2 + 135^2 .

It is a cyclic number.

It is not a de Polignac number, because 2787121 - 2¹ = 2787119 is a prime.

Together with 2787119, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 2787121.

It is not a weakly prime, because it can be changed into another prime (2787181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1393560 + 1393561.

It is an arithmetic number, because the mean of its divisors is an integer number (1393561).

2^2787121 is an apocalyptic number.

It is an amenable number.

2787121 is a deficient number, since it is larger than the sum of its proper divisors (1).

2787121 is an equidigital number, since it uses as much as digits as its factorization.

2787121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1568, while the sum is 28.

The square root of 2787121 is about 1669.4672803023. The cubic root of 2787121 is about 140.7295420820.

The spelling of 2787121 in words is "two million, seven hundred eighty-seven thousand, one hundred twenty-one".