21289918810 has 12 divisors (see below), whose sum is σ = 38322684414. Its totient is φ = 8515782960.

The previous prime is 21289918787. The next prime is 21289918829. The reversal of 21289918810 is 1881998212.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 6639479289 + 14650439521 = 81483^2 + 121039^2 .

It is a super-2 number, since 2×21289918810² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 438340 + ... + 484480.

Almost surely, 2^21289918810 is an apocalyptic number.

21289918810 is a deficient number, since it is larger than the sum of its proper divisors (17032765604).

21289918810 is an frugal number, since it uses more digits than its factorization.

21289918810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92289 (or 46148 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 49.

The spelling of 21289918810 in words is "twenty-one billion, two hundred eighty-nine million, nine hundred eighteen thousand, eight hundred ten".