21001111021000 has 96 divisors (see below), whose sum is σ = 54016246360440. Its totient is φ = 7636767600000.

The previous prime is 21001111020979. The next prime is 21001111021027. The reversal of 21001111021000 is 12011110012.

It can be written as a sum of positive squares in 4 ways, for example, as 10867215530116 + 10133895490884 = 3296546^2 + 3183378^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 86660451 + ... + 86902450.

Almost surely, 2^{21001111021000} is an apocalyptic number.

21001111021000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001111021000 is an abundant number, since it is smaller than the sum of its proper divisors (33015135339440).

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

21001111021000 is a wasteful number, since it uses less digits than its factorization.

21001111021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173562944 (or 173562919 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21001111021000 its reverse (12011110012), we get a palindrome (21013122131012).

The spelling of 21001111021000 in words is "twenty-one trillion, one billion, one hundred eleven million, twenty-one thousand".