21878872793 has 2 divisors, whose sum is σ = 21878872794. Its totient is φ = 21878872792.

The previous prime is 21878872787. The next prime is 21878872801. The reversal of 21878872793 is 39727887812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20372423824 + 1506448969 = 142732^2 + 38813^2 .

It is a cyclic number.

It is not a de Polignac number, because 21878872793 - 2⁴ = 21878872777 is a prime.

It is not a weakly prime, because it can be changed into another prime (21878872753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10939436396 + 10939436397.

It is an arithmetic number, because the mean of its divisors is an integer number (10939436397).

Almost surely, 2^21878872793 is an apocalyptic number.

It is an amenable number.

21878872793 is a deficient number, since it is larger than the sum of its proper divisors (1).

21878872793 is an equidigital number, since it uses as much as digits as its factorization.

21878872793 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18966528, while the sum is 62.

The spelling of 21878872793 in words is "twenty-one billion, eight hundred seventy-eight million, eight hundred seventy-two thousand, seven hundred ninety-three".