21122121001200 has 60 divisors (see below), whose sum is σ = 67661194277688. Its totient is φ = 5632565600000.

The previous prime is 21122121001187. The next prime is 21122121001277. The reversal of 21122121001200 is 210012122112.

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×21122121001200² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21122121001200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8800882551 + ... + 8800884950.

Almost surely, 2^{21122121001200} is an apocalyptic number.

21122121001200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21122121001200 is an abundant number, since it is smaller than the sum of its proper divisors (46539073276488).

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

21122121001200 is a wasteful number, since it uses less digits than its factorization.

21122121001200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17601767522 (or 17601767511 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21122121001200 its reverse (210012122112), we get a palindrome (21332133123312).

The spelling of 21122121001200 in words is "twenty-one trillion, one hundred twenty-two billion, one hundred twenty-one million, one thousand, two hundred".