400406987 has 2 divisors, whose sum is σ = 400406988. Its totient is φ = 400406986.

The previous prime is 400406953. The next prime is 400407011. The reversal of 400406987 is 789604004.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400406987 - 2¹⁰ = 400405963 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400406987.

It is not a weakly prime, because it can be changed into another prime (400406917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200203493 + 200203494.

It is an arithmetic number, because the mean of its divisors is an integer number (200203494).

Almost surely, 2^400406987 is an apocalyptic number.

400406987 is a deficient number, since it is larger than the sum of its proper divisors (1).

400406987 is an equidigital number, since it uses as much as digits as its factorization.

400406987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 400406987 is about 20010.1720882155. The cubic root of 400406987 is about 737.0561071782.

The spelling of 400406987 in words is "four hundred million, four hundred six thousand, nine hundred eighty-seven".