42923821 has 2 divisors, whose sum is σ = 42923822. Its totient is φ = 42923820.

The previous prime is 42923791. The next prime is 42923833. The reversal of 42923821 is 12832924.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42068196 + 855625 = 6486^2 + 925^2 .

It is a cyclic number.

It is not a de Polignac number, because 42923821 - 2⁵ = 42923789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42923851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21461910 + 21461911.

It is an arithmetic number, because the mean of its divisors is an integer number (21461911).

Almost surely, 2^42923821 is an apocalyptic number.

It is an amenable number.

42923821 is a deficient number, since it is larger than the sum of its proper divisors (1).

42923821 is an equidigital number, since it uses as much as digits as its factorization.

42923821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 31.

The square root of 42923821 is about 6551.6273550928. The cubic root of 42923821 is about 350.1327958672.

The spelling of 42923821 in words is "forty-two million, nine hundred twenty-three thousand, eight hundred twenty-one".