2278421 has 2 divisors, whose sum is σ = 2278422. Its totient is φ = 2278420.

The previous prime is 2278379. The next prime is 2278429. The reversal of 2278421 is 1248722.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2208196 + 70225 = 1486^2 + 265^2 .

It is a cyclic number.

It is not a de Polignac number, because 2278421 - 2¹⁸ = 2016277 is a prime.

It is equal to p₁₆₈₀₆₅ and since 2278421 and 168065 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2278429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1139210 + 1139211.

It is an arithmetic number, because the mean of its divisors is an integer number (1139211).

2^2278421 is an apocalyptic number.

It is an amenable number.

2278421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2278421 is an equidigital number, since it uses as much as digits as its factorization.

2278421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1792, while the sum is 26.

The square root of 2278421 is about 1509.4439373491. The cubic root of 2278421 is about 131.5864967991.

The spelling of 2278421 in words is "two million, two hundred seventy-eight thousand, four hundred twenty-one".