39939421 has 2 divisors, whose sum is σ = 39939422. Its totient is φ = 39939420.

The previous prime is 39939407. The next prime is 39939451. The reversal of 39939421 is 12493993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31236921 + 8702500 = 5589^2 + 2950^2 .

It is an emirp because it is prime and its reverse (12493993) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39939421 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 (39939451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19969710 + 19969711.

It is an arithmetic number, because the mean of its divisors is an integer number (19969711).

Almost surely, 2^39939421 is an apocalyptic number.

It is an amenable number.

39939421 is a deficient number, since it is larger than the sum of its proper divisors (1).

39939421 is an equidigital number, since it uses as much as digits as its factorization.

39939421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 52488, while the sum is 40.

The square root of 39939421 is about 6319.7643152257. The cubic root of 39939421 is about 341.8224543836.

The spelling of 39939421 in words is "thirty-nine million, nine hundred thirty-nine thousand, four hundred twenty-one".