21001200222021 has 16 divisors (see below), whose sum is σ = 29222706585984. Its totient is φ = 13390398895104.

The previous prime is 21001200221999. The next prime is 21001200222073. The reversal of 21001200222021 is 12022200210012.

It is not a de Polignac number, because 21001200222021 - 2⁶ = 21001200221957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001200226021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18429316 + ... + 19535661.

It is an arithmetic number, because the mean of its divisors is an integer number (1826419161624).

Almost surely, 2^{21001200222021} is an apocalyptic number.

It is an amenable number.

21001200222021 is a deficient number, since it is larger than the sum of its proper divisors (8221506363963).

21001200222021 is a wasteful number, since it uses less digits than its factorization.

21001200222021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37973020.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21001200222021 its reverse (12022200210012), we get a palindrome (33023400432033).

The spelling of 21001200222021 in words is "twenty-one trillion, one billion, two hundred million, two hundred twenty-two thousand, twenty-one".