21200624161 has 2 divisors, whose sum is σ = 21200624162. Its totient is φ = 21200624160.

The previous prime is 21200624143. The next prime is 21200624171. The reversal of 21200624161 is 16142600212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17944209936 + 3256414225 = 133956^2 + 57065^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200624161 - 2⁷ = 21200624033 is a prime.

It is not a weakly prime, because it can be changed into another prime (21200624111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600312080 + 10600312081.

It is an arithmetic number, because the mean of its divisors is an integer number (10600312081).

Almost surely, 2^21200624161 is an apocalyptic number.

It is an amenable number.

21200624161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200624161 is an equidigital number, since it uses as much as digits as its factorization.

21200624161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 25.

The spelling of 21200624161 in words is "twenty-one billion, two hundred million, six hundred twenty-four thousand, one hundred sixty-one".