21301622777 has 2 divisors, whose sum is σ = 21301622778. Its totient is φ = 21301622776.

The previous prime is 21301622767. The next prime is 21301622789. The reversal of 21301622777 is 77722610312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15726163216 + 5575459561 = 125404^2 + 74669^2 .

It is a cyclic number.

It is not a de Polignac number, because 21301622777 - 2⁸ = 21301622521 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21301622777.

It is not a weakly prime, because it can be changed into another prime (21301622767) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10650811388 + 10650811389.

It is an arithmetic number, because the mean of its divisors is an integer number (10650811389).

Almost surely, 2^21301622777 is an apocalyptic number.

It is an amenable number.

21301622777 is a deficient number, since it is larger than the sum of its proper divisors (1).

21301622777 is an equidigital number, since it uses as much as digits as its factorization.

21301622777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 49392, while the sum is 38.

The spelling of 21301622777 in words is "twenty-one billion, three hundred one million, six hundred twenty-two thousand, seven hundred seventy-seven".