39865421 has 2 divisors, whose sum is σ = 39865422. Its totient is φ = 39865420.

The previous prime is 39865409. The next prime is 39865433. The reversal of 39865421 is 12456893.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (39865409) and next prime (39865433).

It can be written as a sum of positive squares in only one way, i.e., 29041321 + 10824100 = 5389^2 + 3290^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39865421 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39865621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19932710 + 19932711.

It is an arithmetic number, because the mean of its divisors is an integer number (19932711).

Almost surely, 2^39865421 is an apocalyptic number.

It is an amenable number.

39865421 is a deficient number, since it is larger than the sum of its proper divisors (1).

39865421 is an equidigital number, since it uses as much as digits as its factorization.

39865421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 38.

The square root of 39865421 is about 6313.9069521177. The cubic root of 39865421 is about 341.6112136324.

The spelling of 39865421 in words is "thirty-nine million, eight hundred sixty-five thousand, four hundred twenty-one".