21211001200 has 30 divisors (see below), whose sum is σ = 50959431344. Its totient is φ = 8484400320.

The previous prime is 21211001197. The next prime is 21211001219. The reversal of 21211001200 is 210011212.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 26513352 + ... + 26514151.

Almost surely, 2^21211001200 is an apocalyptic number.

21211001200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211001200 is an abundant number, since it is smaller than the sum of its proper divisors (29748430144).

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

21211001200 is a wasteful number, since it uses less digits than its factorization.

21211001200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53027521 (or 53027510 counting only the distinct ones).

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

Adding to 21211001200 its reverse (210011212), we get a palindrome (21421012412).

The spelling of 21211001200 in words is "twenty-one billion, two hundred eleven million, one thousand, two hundred".