21061243203 has 128 divisors (see below), whose sum is σ = 40182718464. Its totient is φ = 9443174400.

The previous prime is 21061243187. The next prime is 21061243349. The reversal of 21061243203 is 30234216012.

It is not a de Polignac number, because 21061243203 - 2⁴ = 21061243187 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21061241203) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 8320048 + ... + 8322578.

It is an arithmetic number, because the mean of its divisors is an integer number (313927488).

Almost surely, 2^21061243203 is an apocalyptic number.

21061243203 is a deficient number, since it is larger than the sum of its proper divisors (19121475261).

21061243203 is a wasteful number, since it uses less digits than its factorization.

21061243203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2745.

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21061243203 its reverse (30234216012), we get a palindrome (51295459215).

The spelling of 21061243203 in words is "twenty-one billion, sixty-one million, two hundred forty-three thousand, two hundred three".