21190042639 has 2 divisors, whose sum is σ = 21190042640. Its totient is φ = 21190042638.

The previous prime is 21190042603. The next prime is 21190042651. The reversal of 21190042639 is 93624009112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21190042639 - 2¹¹ = 21190040591 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21190042598 and 21190042607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21190040639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10595021319 + 10595021320.

It is an arithmetic number, because the mean of its divisors is an integer number (10595021320).

Almost surely, 2^21190042639 is an apocalyptic number.

21190042639 is a deficient number, since it is larger than the sum of its proper divisors (1).

21190042639 is an equidigital number, since it uses as much as digits as its factorization.

21190042639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23328, while the sum is 37.

The spelling of 21190042639 in words is "twenty-one billion, one hundred ninety million, forty-two thousand, six hundred thirty-nine".