42400087 has 2 divisors, whose sum is σ = 42400088. Its totient is φ = 42400086.

The previous prime is 42400081. The next prime is 42400121. The reversal of 42400087 is 78000424.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42400087 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42400081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21200043 + 21200044.

It is an arithmetic number, because the mean of its divisors is an integer number (21200044).

Almost surely, 2^42400087 is an apocalyptic number.

42400087 is a deficient number, since it is larger than the sum of its proper divisors (1).

42400087 is an equidigital number, since it uses as much as digits as its factorization.

42400087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1792, while the sum is 25.

The square root of 42400087 is about 6511.5349188959. The cubic root of 42400087 is about 348.7029187523.

The spelling of 42400087 in words is "forty-two million, four hundred thousand, eighty-seven".