16421677777 has 2 divisors, whose sum is σ = 16421677778. Its totient is φ = 16421677776.

The previous prime is 16421677763. The next prime is 16421677841. The reversal of 16421677777 is 77777612461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15300700416 + 1120977361 = 123696^2 + 33481^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16421677777 is a prime.

It is not a weakly prime, because it can be changed into another prime (16421677277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8210838888 + 8210838889.

It is an arithmetic number, because the mean of its divisors is an integer number (8210838889).

Almost surely, 2^16421677777 is an apocalyptic number.

It is an amenable number.

16421677777 is a deficient number, since it is larger than the sum of its proper divisors (1).

16421677777 is an equidigital number, since it uses as much as digits as its factorization.

16421677777 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4840416, while the sum is 55.

The spelling of 16421677777 in words is "sixteen billion, four hundred twenty-one million, six hundred seventy-seven thousand, seven hundred seventy-seven".