21277334641 has 2 divisors, whose sum is σ = 21277334642. Its totient is φ = 21277334640.

The previous prime is 21277334587. The next prime is 21277334647. The reversal of 21277334641 is 14643377212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21229655616 + 47679025 = 145704^2 + 6905^2 .

It is a cyclic number.

It is not a de Polignac number, because 21277334641 - 2¹⁵ = 21277301873 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21277334594 and 21277334603.

It is not a weakly prime, because it can be changed into another prime (21277334647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10638667320 + 10638667321.

It is an arithmetic number, because the mean of its divisors is an integer number (10638667321).

Almost surely, 2^21277334641 is an apocalyptic number.

It is an amenable number.

21277334641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21277334641 is an equidigital number, since it uses as much as digits as its factorization.

21277334641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 169344, while the sum is 40.

The spelling of 21277334641 in words is "twenty-one billion, two hundred seventy-seven million, three hundred thirty-four thousand, six hundred forty-one".