2642821 has 2 divisors, whose sum is σ = 2642822. Its totient is φ = 2642820.

The previous prime is 2642797. The next prime is 2642839. The reversal of 2642821 is 1282462.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2608225 + 34596 = 1615^2 + 186^2 .

It is a cyclic number.

It is not a de Polignac number, because 2642821 - 2⁵ = 2642789 is a prime.

2642821 is a lucky number.

It is equal to p₁₉₂₇₆₀ and since 2642821 and 192760 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 (2642891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1321410 + 1321411.

It is an arithmetic number, because the mean of its divisors is an integer number (1321411).

2^2642821 is an apocalyptic number.

It is an amenable number.

2642821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2642821 is an equidigital number, since it uses as much as digits as its factorization.

2642821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 25.

The square root of 2642821 is about 1625.6755518860. The cubic root of 2642821 is about 138.2576751165.

The spelling of 2642821 in words is "two million, six hundred forty-two thousand, eight hundred twenty-one".