40004389 has 2 divisors, whose sum is σ = 40004390. Its totient is φ = 40004388.

The previous prime is 40004357. The next prime is 40004399. The reversal of 40004389 is 98340004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34316164 + 5688225 = 5858^2 + 2385^2 .

It is a cyclic number.

It is not a de Polignac number, because 40004389 - 2⁵ = 40004357 is a prime.

It is a super-2 number, since 2×40004389² = 3200702278526642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40004309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20002194 + 20002195.

It is an arithmetic number, because the mean of its divisors is an integer number (20002195).

Almost surely, 2^40004389 is an apocalyptic number.

It is an amenable number.

40004389 is a deficient number, since it is larger than the sum of its proper divisors (1).

40004389 is an equidigital number, since it uses as much as digits as its factorization.

40004389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 40004389 is about 6324.9022917354. The cubic root of 40004389 is about 342.0076973519.

The spelling of 40004389 in words is "forty million, four thousand, three hundred eighty-nine".