21203010061 has 2 divisors, whose sum is σ = 21203010062. Its totient is φ = 21203010060.

The previous prime is 21203010053. The next prime is 21203010083. The reversal of 21203010061 is 16001030212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15480087561 + 5722922500 = 124419^2 + 75650^2 .

It is a cyclic number.

It is not a de Polignac number, because 21203010061 - 2³ = 21203010053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21203010001) 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, 10601505030 + 10601505031.

It is an arithmetic number, because the mean of its divisors is an integer number (10601505031).

Almost surely, 2^21203010061 is an apocalyptic number.

It is an amenable number.

21203010061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203010061 is an equidigital number, since it uses as much as digits as its factorization.

21203010061 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21203010061 its reverse (16001030212), we get a palindrome (37204040273).

The spelling of 21203010061 in words is "twenty-one billion, two hundred three million, ten thousand, sixty-one".