21203115273 has 24 divisors (see below), whose sum is σ = 31383924936. Its totient is φ = 13786156800.

The previous prime is 21203115257. The next prime is 21203115277. The reversal of 21203115273 is 37251130212.

21203115273 is a `hidden beast` number, since 2 + 120 + 3 + 11 + 527 + 3 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 49449024 + 21153666249 = 7032^2 + 145443^2 .

It is not a de Polignac number, because 21203115273 - 2⁴ = 21203115257 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21203115277) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1423203 + ... + 1438023.

It is an arithmetic number, because the mean of its divisors is an integer number (1307663539).

Almost surely, 2^21203115273 is an apocalyptic number.

It is an amenable number.

21203115273 is a deficient number, since it is larger than the sum of its proper divisors (10180809663).

21203115273 is a wasteful number, since it uses less digits than its factorization.

21203115273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18745 (or 18742 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 27.

Adding to 21203115273 its reverse (37251130212), we get a palindrome (58454245485).

The spelling of 21203115273 in words is "twenty-one billion, two hundred three million, one hundred fifteen thousand, two hundred seventy-three".