402000491 has 2 divisors, whose sum is σ = 402000492. Its totient is φ = 402000490.

The previous prime is 402000439. The next prime is 402000517. The reversal of 402000491 is 194000204.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 402000491 - 2¹⁸ = 401738347 is a prime.

It is not a weakly prime, because it can be changed into another prime (402000191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201000245 + 201000246.

It is an arithmetic number, because the mean of its divisors is an integer number (201000246).

Almost surely, 2^402000491 is an apocalyptic number.

402000491 is a deficient number, since it is larger than the sum of its proper divisors (1).

402000491 is an equidigital number, since it uses as much as digits as its factorization.

402000491 is an odious number, because the sum of its binary digits is odd.

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

The square root of 402000491 is about 20049.9499001868. The cubic root of 402000491 is about 738.0325696855.

Adding to 402000491 its reverse (194000204), we get a palindrome (596000695).

The spelling of 402000491 in words is "four hundred two million, four hundred ninety-one", and thus it is an aban number.