21421399177 has 2 divisors, whose sum is σ = 21421399178. Its totient is φ = 21421399176.

The previous prime is 21421399171. The next prime is 21421399183. The reversal of 21421399177 is 77199312412.

It is a balanced prime because it is at equal distance from previous prime (21421399171) and next prime (21421399183).

It can be written as a sum of positive squares in only one way, i.e., 20723329936 + 698069241 = 143956^2 + 26421^2 .

It is a cyclic number.

It is not a de Polignac number, because 21421399177 - 2³ = 21421399169 is a prime.

It is not a weakly prime, because it can be changed into another prime (21421399171) 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, 10710699588 + 10710699589.

It is an arithmetic number, because the mean of its divisors is an integer number (10710699589).

Almost surely, 2^21421399177 is an apocalyptic number.

It is an amenable number.

21421399177 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421399177 is an equidigital number, since it uses as much as digits as its factorization.

21421399177 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 190512, while the sum is 46.

The spelling of 21421399177 in words is "twenty-one billion, four hundred twenty-one million, three hundred ninety-nine thousand, one hundred seventy-seven".