840038399 has 2 divisors, whose sum is σ = 840038400. Its totient is φ = 840038398.

The previous prime is 840038387. The next prime is 840038449. The reversal of 840038399 is 993830048.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 840038399 - 2⁴ = 840038383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (840038369) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 420019199 + 420019200.

It is an arithmetic number, because the mean of its divisors is an integer number (420019200).

Almost surely, 2^840038399 is an apocalyptic number.

840038399 is a deficient number, since it is larger than the sum of its proper divisors (1).

840038399 is an equidigital number, since it uses as much as digits as its factorization.

840038399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 44.

The square root of 840038399 is about 28983.4159304938. The cubic root of 840038399 is about 943.5531732038.

The spelling of 840038399 in words is "eight hundred forty million, thirty-eight thousand, three hundred ninety-nine".