1020688639 has 2 divisors, whose sum is σ = 1020688640. Its totient is φ = 1020688638.

The previous prime is 1020688637. The next prime is 1020688649. The reversal of 1020688639 is 9368860201.

It is a weak prime.

It is an emirp because it is prime and its reverse (9368860201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1020688639 - 2¹ = 1020688637 is a prime.

Together with 1020688637, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1020688595 and 1020688604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1020688637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510344319 + 510344320.

It is an arithmetic number, because the mean of its divisors is an integer number (510344320).

Almost surely, 2^1020688639 is an apocalyptic number.

1020688639 is a deficient number, since it is larger than the sum of its proper divisors (1).

1020688639 is an equidigital number, since it uses as much as digits as its factorization.

1020688639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 1020688639 is about 31948.2180880249. The cubic root of 1020688639 is about 1006.8491944337.

The spelling of 1020688639 in words is "one billion, twenty million, six hundred eighty-eight thousand, six hundred thirty-nine".