42850021 has 2 divisors, whose sum is σ = 42850022. Its totient is φ = 42850020.

The previous prime is 42850019. The next prime is 42850037. The reversal of 42850021 is 12005824.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42837025 + 12996 = 6545^2 + 114^2 .

It is a cyclic number.

It is not a de Polignac number, because 42850021 - 2¹ = 42850019 is a prime.

It is a super-2 number, since 2×42850021² = 3672248599400882, which contains 22 as substring.

Together with 42850019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 42849974 and 42850001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42850001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21425010 + 21425011.

It is an arithmetic number, because the mean of its divisors is an integer number (21425011).

Almost surely, 2^42850021 is an apocalyptic number.

It is an amenable number.

42850021 is a deficient number, since it is larger than the sum of its proper divisors (1).

42850021 is an equidigital number, since it uses as much as digits as its factorization.

42850021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 42850021 is about 6545.9927436562. The cubic root of 42850021 is about 349.9320167279.

Adding to 42850021 its reverse (12005824), we get a palindrome (54855845).

The spelling of 42850021 in words is "forty-two million, eight hundred fifty thousand, twenty-one".