21477816719 has 2 divisors, whose sum is σ = 21477816720. Its totient is φ = 21477816718.

The previous prime is 21477816697. The next prime is 21477816739. The reversal of 21477816719 is 91761877412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21477816719 - 2¹² = 21477812623 is a prime.

It is a super-2 number, since 2×21477816719² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21477816739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10738908359 + 10738908360.

It is an arithmetic number, because the mean of its divisors is an integer number (10738908360).

Almost surely, 2^21477816719 is an apocalyptic number.

21477816719 is a deficient number, since it is larger than the sum of its proper divisors (1).

21477816719 is an equidigital number, since it uses as much as digits as its factorization.

21477816719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1185408, while the sum is 53.

The spelling of 21477816719 in words is "twenty-one billion, four hundred seventy-seven million, eight hundred sixteen thousand, seven hundred nineteen".