21201001200 has 90 divisors (see below), whose sum is σ = 73573375824. Its totient is φ = 5653599360.

The previous prime is 21201001193. The next prime is 21201001207. The reversal of 21201001200 is 210010212.

It is an interprime number because it is at equal distance from previous prime (21201001193) and next prime (21201001207).

It is a tau number, because it is divible by the number of its divisors (90).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21201001207) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2940984 + ... + 2948183.

Almost surely, 2^21201001200 is an apocalyptic number.

21201001200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21201001200 is an abundant number, since it is smaller than the sum of its proper divisors (52372374624).

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

21201001200 is a wasteful number, since it uses less digits than its factorization.

21201001200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5889191 (or 5889177 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21201001200 its reverse (210010212), we get a palindrome (21411011412).

The spelling of 21201001200 in words is "twenty-one billion, two hundred one million, one thousand, two hundred".