21121828989 has 8 divisors (see below), whose sum is σ = 28163782752. Its totient is φ = 14080547280.

The previous prime is 21121828877. The next prime is 21121829023. The reversal of 21121828989 is 98982812112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21121828989 - 2¹¹ = 21121826941 is a prime.

It is a super-2 number, since 2×21121828989² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121824989) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 89427 + ... + 224144.

It is an arithmetic number, because the mean of its divisors is an integer number (3520472844).

Almost surely, 2^21121828989 is an apocalyptic number.

It is an amenable number.

21121828989 is a deficient number, since it is larger than the sum of its proper divisors (7041953763).

21121828989 is a wasteful number, since it uses less digits than its factorization.

21121828989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336027.

The product of its digits is 331776, while the sum is 51.

The spelling of 21121828989 in words is "twenty-one billion, one hundred twenty-one million, eight hundred twenty-eight thousand, nine hundred eighty-nine".