28780681 has 2 divisors, whose sum is σ = 28780682. Its totient is φ = 28780680.

The previous prime is 28780669. The next prime is 28780693. The reversal of 28780681 is 18608782.

It is a balanced prime because it is at equal distance from previous prime (28780669) and next prime (28780693).

It can be written as a sum of positive squares in only one way, i.e., 27657081 + 1123600 = 5259^2 + 1060^2 .

It is a cyclic number.

It is not a de Polignac number, because 28780681 - 2¹³ = 28772489 is a prime.

It is a super-2 number, since 2×28780681² = 1656655197647522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28780621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14390340 + 14390341.

It is an arithmetic number, because the mean of its divisors is an integer number (14390341).

Almost surely, 2^28780681 is an apocalyptic number.

It is an amenable number.

28780681 is a deficient number, since it is larger than the sum of its proper divisors (1).

28780681 is an equidigital number, since it uses as much as digits as its factorization.

28780681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 28780681 is about 5364.7629024963. The cubic root of 28780681 is about 306.4552190528.

The spelling of 28780681 in words is "twenty-eight million, seven hundred eighty thousand, six hundred eighty-one".