21932878777 has 2 divisors, whose sum is σ = 21932878778. Its totient is φ = 21932878776.

The previous prime is 21932878769. The next prime is 21932878811. The reversal of 21932878777 is 77787823912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17707358761 + 4225520016 = 133069^2 + 65004^2 .

It is a cyclic number.

It is not a de Polignac number, because 21932878777 - 2³ = 21932878769 is a prime.

It is not a weakly prime, because it can be changed into another prime (21932878717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10966439388 + 10966439389.

It is an arithmetic number, because the mean of its divisors is an integer number (10966439389).

Almost surely, 2^21932878777 is an apocalyptic number.

It is an amenable number.

21932878777 is a deficient number, since it is larger than the sum of its proper divisors (1).

21932878777 is an equidigital number, since it uses as much as digits as its factorization.

21932878777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16595712, while the sum is 61.

The spelling of 21932878777 in words is "twenty-one billion, nine hundred thirty-two million, eight hundred seventy-eight thousand, seven hundred seventy-seven".