42139087 has 2 divisors, whose sum is σ = 42139088. Its totient is φ = 42139086.

The previous prime is 42139063. The next prime is 42139109. The reversal of 42139087 is 78093124.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42139087 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42139007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21069543 + 21069544.

It is an arithmetic number, because the mean of its divisors is an integer number (21069544).

Almost surely, 2^42139087 is an apocalyptic number.

42139087 is a deficient number, since it is larger than the sum of its proper divisors (1).

42139087 is an equidigital number, since it uses as much as digits as its factorization.

42139087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 42139087 is about 6491.4626240933. The cubic root of 42139087 is about 347.9859481489.

It can be divided in two parts, 42 and 139087, that added together give a square (139129 = 373²).

The spelling of 42139087 in words is "forty-two million, one hundred thirty-nine thousand, eighty-seven".