21311111000 has 32 divisors (see below), whose sum is σ = 49868002080. Its totient is φ = 8524444000.

The previous prime is 21311110991. The next prime is 21311111023. The reversal of 21311111000 is 11111312.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10654556 + ... + 10656555.

It is an arithmetic number, because the mean of its divisors is an integer number (1558375065).

Almost surely, 2^21311111000 is an apocalyptic number.

21311111000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311111000 is an abundant number, since it is smaller than the sum of its proper divisors (28556891080).

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

21311111000 is a wasteful number, since it uses less digits than its factorization.

21311111000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21311132 (or 21311118 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 11.

Adding to 21311111000 its reverse (11111312), we get a palindrome (21322222312).

The spelling of 21311111000 in words is "twenty-one billion, three hundred eleven million, one hundred eleven thousand".