70639 has 2 divisors, whose sum is σ = 70640. Its totient is φ = 70638.

The previous prime is 70627. The next prime is 70657. The reversal of 70639 is 93607.

It is a weak prime.

It is an emirp because it is prime and its reverse (93607) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 70639 - 2⁵ = 70607 is a prime.

It is an Ulam number.

70639 is a lucky number.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35319 + 35320.

It is an arithmetic number, because the mean of its divisors is an integer number (35320).

2⁷⁰⁶³⁹ is an apocalyptic number.

70639 is a deficient number, since it is larger than the sum of its proper divisors (1).

70639 is an equidigital number, since it uses as much as digits as its factorization.

70639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1134, while the sum is 25.

The square root of 70639 is about 265.7799841975. The cubic root of 70639 is about 41.3378781567.

The spelling of 70639 in words is "seventy thousand, six hundred thirty-nine".