21003136177 has 2 divisors, whose sum is σ = 21003136178. Its totient is φ = 21003136176.

The previous prime is 21003136087. The next prime is 21003136211. The reversal of 21003136177 is 77163130012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17624155536 + 3378980641 = 132756^2 + 58129^2 .

It is a cyclic number.

It is not a de Polignac number, because 21003136177 - 2²⁷ = 20868918449 is a prime.

It is a super-2 number, since 2×21003136177² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21003136277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501568088 + 10501568089.

It is an arithmetic number, because the mean of its divisors is an integer number (10501568089).

Almost surely, 2^21003136177 is an apocalyptic number.

It is an amenable number.

21003136177 is a deficient number, since it is larger than the sum of its proper divisors (1).

21003136177 is an equidigital number, since it uses as much as digits as its factorization.

21003136177 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 31.

Adding to 21003136177 its reverse (77163130012), we get a palindrome (98166266189).

The spelling of 21003136177 in words is "twenty-one billion, three million, one hundred thirty-six thousand, one hundred seventy-seven".