21773390077 has 2 divisors, whose sum is σ = 21773390078. Its totient is φ = 21773390076.

The previous prime is 21773390071. The next prime is 21773390141. The reversal of 21773390077 is 77009337712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13468530916 + 8304859161 = 116054^2 + 91131^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21773390077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21773390071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10886695038 + 10886695039.

It is an arithmetic number, because the mean of its divisors is an integer number (10886695039).

Almost surely, 2^21773390077 is an apocalyptic number.

It is an amenable number.

21773390077 is a deficient number, since it is larger than the sum of its proper divisors (1).

21773390077 is an equidigital number, since it uses as much as digits as its factorization.

21773390077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 388962, while the sum is 46.

The spelling of 21773390077 in words is "twenty-one billion, seven hundred seventy-three million, three hundred ninety thousand, seventy-seven".