21199707677 has 2 divisors, whose sum is σ = 21199707678. Its totient is φ = 21199707676.

The previous prime is 21199707667. The next prime is 21199707689. The reversal of 21199707677 is 77670799112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21123424921 + 76282756 = 145339^2 + 8734^2 .

It is a cyclic number.

It is not a de Polignac number, because 21199707677 - 2¹⁰ = 21199706653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21199707667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10599853838 + 10599853839.

It is an arithmetic number, because the mean of its divisors is an integer number (10599853839).

Almost surely, 2^21199707677 is an apocalyptic number.

It is an amenable number.

21199707677 is a deficient number, since it is larger than the sum of its proper divisors (1).

21199707677 is an equidigital number, since it uses as much as digits as its factorization.

21199707677 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2333772, while the sum is 56.

The spelling of 21199707677 in words is "twenty-one billion, one hundred ninety-nine million, seven hundred seven thousand, six hundred seventy-seven".