21135606277 has 2 divisors, whose sum is σ = 21135606278. Its totient is φ = 21135606276.

The previous prime is 21135606259. The next prime is 21135606293. The reversal of 21135606277 is 77260653112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15099248641 + 6036357636 = 122879^2 + 77694^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21135606277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21135606577) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10567803138 + 10567803139.

It is an arithmetic number, because the mean of its divisors is an integer number (10567803139).

Almost surely, 2^21135606277 is an apocalyptic number.

It is an amenable number.

21135606277 is a deficient number, since it is larger than the sum of its proper divisors (1).

21135606277 is an equidigital number, since it uses as much as digits as its factorization.

21135606277 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 105840, while the sum is 40.

The spelling of 21135606277 in words is "twenty-one billion, one hundred thirty-five million, six hundred six thousand, two hundred seventy-seven".