2800002781 has 2 divisors, whose sum is σ = 2800002782. Its totient is φ = 2800002780.

The previous prime is 2800002763. The next prime is 2800002797. The reversal of 2800002781 is 1872000082.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2029052025 + 770950756 = 45045^2 + 27766^2 .

It is a cyclic number.

It is not a de Polignac number, because 2800002781 - 2¹¹ = 2800000733 is a prime.

It is a super-2 number, since 2×2800002781² = 15680031147215467922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2800002721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1400001390 + 1400001391.

It is an arithmetic number, because the mean of its divisors is an integer number (1400001391).

Almost surely, 2^2800002781 is an apocalyptic number.

It is an amenable number.

2800002781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2800002781 is an equidigital number, since it uses as much as digits as its factorization.

2800002781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1792, while the sum is 28.

The square root of 2800002781 is about 52915.0524992653. The cubic root of 2800002781 is about 1409.4602130447.

The spelling of 2800002781 in words is "two billion, eight hundred million, two thousand, seven hundred eighty-one".