42823421 has 2 divisors, whose sum is σ = 42823422. Its totient is φ = 42823420.

The previous prime is 42823409. The next prime is 42823453. The reversal of 42823421 is 12432824.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37039396 + 5784025 = 6086^2 + 2405^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42823421 is a prime.

It is a super-2 number, since 2×42823421² = 3667690772286482, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42823621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21411710 + 21411711.

It is an arithmetic number, because the mean of its divisors is an integer number (21411711).

Almost surely, 2^42823421 is an apocalyptic number.

It is an amenable number.

42823421 is a deficient number, since it is larger than the sum of its proper divisors (1).

42823421 is an equidigital number, since it uses as much as digits as its factorization.

42823421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 26.

The square root of 42823421 is about 6543.9606508597. The cubic root of 42823421 is about 349.8595926608.

The spelling of 42823421 in words is "forty-two million, eight hundred twenty-three thousand, four hundred twenty-one".