211020021077 has 2 divisors, whose sum is σ = 211020021078. Its totient is φ = 211020021076.

The previous prime is 211020021073. The next prime is 211020021127. The reversal of 211020021077 is 770120020112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 209557035076 + 1462986001 = 457774^2 + 38249^2 .

It is a cyclic number.

It is not a de Polignac number, because 211020021077 - 2² = 211020021073 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211020021073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105510010538 + 105510010539.

It is an arithmetic number, because the mean of its divisors is an integer number (105510010539).

Almost surely, 2^211020021077 is an apocalyptic number.

It is an amenable number.

211020021077 is a deficient number, since it is larger than the sum of its proper divisors (1).

211020021077 is an equidigital number, since it uses as much as digits as its factorization.

211020021077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 392, while the sum is 23.

Adding to 211020021077 its reverse (770120020112), we get a palindrome (981140041189).

The spelling of 211020021077 in words is "two hundred eleven billion, twenty million, twenty-one thousand, seventy-seven".