21212075404777 has 2 divisors, whose sum is σ = 21212075404778. Its totient is φ = 21212075404776.

The previous prime is 21212075404739. The next prime is 21212075404787. The reversal of 21212075404777 is 77740457021212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20256336495616 + 955738909161 = 4500704^2 + 977619^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212075404777 - 2⁷ = 21212075404649 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21212075404777.

It is not a weakly prime, because it can be changed into another prime (21212075404717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606037702388 + 10606037702389.

It is an arithmetic number, because the mean of its divisors is an integer number (10606037702389).

Almost surely, 2^{21212075404777} is an apocalyptic number.

It is an amenable number.

21212075404777 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212075404777 is an equidigital number, since it uses as much as digits as its factorization.

21212075404777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536640, while the sum is 49.

The spelling of 21212075404777 in words is "twenty-one trillion, two hundred twelve billion, seventy-five million, four hundred four thousand, seven hundred seventy-seven".