21345288277 has 2 divisors, whose sum is σ = 21345288278. Its totient is φ = 21345288276.

The previous prime is 21345288269. The next prime is 21345288287. The reversal of 21345288277 is 77288254312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21016010961 + 329277316 = 144969^2 + 18146^2 .

It is a cyclic number.

It is not a de Polignac number, because 21345288277 - 2³ = 21345288269 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21345288277.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21345288227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10672644138 + 10672644139.

It is an arithmetic number, because the mean of its divisors is an integer number (10672644139).

Almost surely, 2^21345288277 is an apocalyptic number.

It is an amenable number.

21345288277 is a deficient number, since it is larger than the sum of its proper divisors (1).

21345288277 is an equidigital number, since it uses as much as digits as its factorization.

21345288277 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1505280, while the sum is 49.

The spelling of 21345288277 in words is "twenty-one billion, three hundred forty-five million, two hundred eighty-eight thousand, two hundred seventy-seven".