21011122000 has 80 divisors (see below), whose sum is σ = 55423577664. Its totient is φ = 7640400000.

The previous prime is 21011121979. The next prime is 21011122009. The reversal of 21011122000 is 22111012.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011122009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 455526 + ... + 499525.

Almost surely, 2^21011122000 is an apocalyptic number.

21011122000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011122000 is an abundant number, since it is smaller than the sum of its proper divisors (34412455664).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21011122000 is a wasteful number, since it uses less digits than its factorization.

21011122000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 955085 (or 955069 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21011122000 its reverse (22111012), we get a palindrome (21033233012).

The spelling of 21011122000 in words is "twenty-one billion, eleven million, one hundred twenty-two thousand".