39423821 has 2 divisors, whose sum is σ = 39423822. Its totient is φ = 39423820.

The previous prime is 39423809. The next prime is 39423823. The reversal of 39423821 is 12832493.

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., 24900100 + 14523721 = 4990^2 + 3811^2 .

It is an emirp because it is prime and its reverse (12832493) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 39423821 - 2⁶ = 39423757 is a prime.

Together with 39423823, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39423823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19711910 + 19711911.

It is an arithmetic number, because the mean of its divisors is an integer number (19711911).

Almost surely, 2^39423821 is an apocalyptic number.

It is an amenable number.

39423821 is a deficient number, since it is larger than the sum of its proper divisors (1).

39423821 is an equidigital number, since it uses as much as digits as its factorization.

39423821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 32.

The square root of 39423821 is about 6278.8391443005. The cubic root of 39423821 is about 340.3451541087.

The spelling of 39423821 in words is "thirty-nine million, four hundred twenty-three thousand, eight hundred twenty-one".