21770779967 has 2 divisors, whose sum is σ = 21770779968. Its totient is φ = 21770779966.

The previous prime is 21770779957. The next prime is 21770779969. The reversal of 21770779967 is 76997707712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21770779967 - 2⁶ = 21770779903 is a prime.

Together with 21770779969, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21770779969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10885389983 + 10885389984.

It is an arithmetic number, because the mean of its divisors is an integer number (10885389984).

Almost surely, 2^21770779967 is an apocalyptic number.

21770779967 is a deficient number, since it is larger than the sum of its proper divisors (1).

21770779967 is an equidigital number, since it uses as much as digits as its factorization.

21770779967 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16336404, while the sum is 62.

The spelling of 21770779967 in words is "twenty-one billion, seven hundred seventy million, seven hundred seventy-nine thousand, nine hundred sixty-seven".