19621581839 has 2 divisors, whose sum is σ = 19621581840. Its totient is φ = 19621581838.

The previous prime is 19621581829. The next prime is 19621581841. The reversal of 19621581839 is 93818512691.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19621581839 - 2¹² = 19621577743 is a prime.

Together with 19621581841, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19621581829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9810790919 + 9810790920.

It is an arithmetic number, because the mean of its divisors is an integer number (9810790920).

Almost surely, 2^19621581839 is an apocalyptic number.

19621581839 is a deficient number, since it is larger than the sum of its proper divisors (1).

19621581839 is an equidigital number, since it uses as much as digits as its factorization.

19621581839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 933120, while the sum is 53.

The spelling of 19621581839 in words is "nineteen billion, six hundred twenty-one million, five hundred eighty-one thousand, eight hundred thirty-nine".