19928143639 has 2 divisors, whose sum is σ = 19928143640. Its totient is φ = 19928143638.

The previous prime is 19928143553. The next prime is 19928143663. The reversal of 19928143639 is 93634182991.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19928143639 - 2²¹ = 19926046487 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19928143639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19928146639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9964071819 + 9964071820.

It is an arithmetic number, because the mean of its divisors is an integer number (9964071820).

Almost surely, 2^19928143639 is an apocalyptic number.

19928143639 is a deficient number, since it is larger than the sum of its proper divisors (1).

19928143639 is an equidigital number, since it uses as much as digits as its factorization.

19928143639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2519424, while the sum is 55.

The spelling of 19928143639 in words is "nineteen billion, nine hundred twenty-eight million, one hundred forty-three thousand, six hundred thirty-nine".