4778021 has 2 divisors, whose sum is σ = 4778022. Its totient is φ = 4778020.

The previous prime is 4778009. The next prime is 4778027. The reversal of 4778021 is 1208774.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3556996 + 1221025 = 1886^2 + 1105^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-4778021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4778027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2389010 + 2389011.

It is an arithmetic number, because the mean of its divisors is an integer number (2389011).

Almost surely, 2^4778021 is an apocalyptic number.

It is an amenable number.

4778021 is a deficient number, since it is larger than the sum of its proper divisors (1).

4778021 is an equidigital number, since it uses as much as digits as its factorization.

4778021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 4778021 is about 2185.8684772877. The cubic root of 4778021 is about 168.4286695414.

The spelling of 4778021 in words is "four million, seven hundred seventy-eight thousand, twenty-one".