39904429 has 2 divisors, whose sum is σ = 39904430. Its totient is φ = 39904428.

The previous prime is 39904421. The next prime is 39904433. The reversal of 39904429 is 92440993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39715204 + 189225 = 6302^2 + 435^2 .

It is a cyclic number.

It is not a de Polignac number, because 39904429 - 2³ = 39904421 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 39904391 and 39904400.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (39904421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19952214 + 19952215.

It is an arithmetic number, because the mean of its divisors is an integer number (19952215).

Almost surely, 2^39904429 is an apocalyptic number.

It is an amenable number.

39904429 is a deficient number, since it is larger than the sum of its proper divisors (1).

39904429 is an equidigital number, since it uses as much as digits as its factorization.

39904429 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 69984, while the sum is 40.

The square root of 39904429 is about 6316.9952509085. The cubic root of 39904429 is about 341.7225986032.

The spelling of 39904429 in words is "thirty-nine million, nine hundred four thousand, four hundred twenty-nine".