400240019 has 2 divisors, whose sum is σ = 400240020. Its totient is φ = 400240018.

The previous prime is 400240003. The next prime is 400240021. The reversal of 400240019 is 910042004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400240019 - 2⁴ = 400240003 is a prime.

It is a super-2 number, since 2×400240019² = 320384145618240722, which contains 22 as substring.

Together with 400240021, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (400240219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200120009 + 200120010.

It is an arithmetic number, because the mean of its divisors is an integer number (200120010).

Almost surely, 2^400240019 is an apocalyptic number.

400240019 is a deficient number, since it is larger than the sum of its proper divisors (1).

400240019 is an equidigital number, since it uses as much as digits as its factorization.

400240019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 400240019 is about 20005.9995751275. Note that the first 3 decimals coincide. The cubic root of 400240019 is about 736.9536431870.

The spelling of 400240019 in words is "four hundred million, two hundred forty thousand, nineteen".