21177034213 has 2 divisors, whose sum is σ = 21177034214. Its totient is φ = 21177034212.

The previous prime is 21177034187. The next prime is 21177034273. The reversal of 21177034213 is 31243077112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21124587649 + 52446564 = 145343^2 + 7242^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21177034213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21177034273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10588517106 + 10588517107.

It is an arithmetic number, because the mean of its divisors is an integer number (10588517107).

Almost surely, 2^21177034213 is an apocalyptic number.

It is an amenable number.

21177034213 is a deficient number, since it is larger than the sum of its proper divisors (1).

21177034213 is an equidigital number, since it uses as much as digits as its factorization.

21177034213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7056, while the sum is 31.

The spelling of 21177034213 in words is "twenty-one billion, one hundred seventy-seven million, thirty-four thousand, two hundred thirteen".