19672821989 has 2 divisors, whose sum is σ = 19672821990. Its totient is φ = 19672821988.

The previous prime is 19672821983. The next prime is 19672822009. The reversal of 19672821989 is 98912827691.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13465745764 + 6207076225 = 116042^2 + 78785^2 .

It is a cyclic number.

It is not a de Polignac number, because 19672821989 - 2⁸ = 19672821733 is a prime.

It is a super-2 number, since 2×19672821989² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19672821983) 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, 9836410994 + 9836410995.

It is an arithmetic number, because the mean of its divisors is an integer number (9836410995).

Almost surely, 2^19672821989 is an apocalyptic number.

It is an amenable number.

19672821989 is a deficient number, since it is larger than the sum of its proper divisors (1).

19672821989 is an equidigital number, since it uses as much as digits as its factorization.

19672821989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7838208, while the sum is 62.

The spelling of 19672821989 in words is "nineteen billion, six hundred seventy-two million, eight hundred twenty-one thousand, nine hundred eighty-nine".