21555342301 has 2 divisors, whose sum is σ = 21555342302. Its totient is φ = 21555342300.

The previous prime is 21555342271. The next prime is 21555342329. The reversal of 21555342301 is 10324355512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10801444900 + 10753897401 = 103930^2 + 103701^2 .

It is a cyclic number.

It is not a de Polignac number, because 21555342301 - 2⁵ = 21555342269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21555342001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10777671150 + 10777671151.

It is an arithmetic number, because the mean of its divisors is an integer number (10777671151).

Almost surely, 2^21555342301 is an apocalyptic number.

It is an amenable number.

21555342301 is a deficient number, since it is larger than the sum of its proper divisors (1).

21555342301 is an equidigital number, since it uses as much as digits as its factorization.

21555342301 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 21555342301 its reverse (10324355512), we get a palindrome (31879697813).

The spelling of 21555342301 in words is "twenty-one billion, five hundred fifty-five million, three hundred forty-two thousand, three hundred one".