21000012012021 has 8 divisors (see below), whose sum is σ = 32000018304064. Its totient is φ = 12000006864000.

The previous prime is 21000012011999. The next prime is 21000012012037. The reversal of 21000012012021 is 12021021000012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21000012012021 - 2⁹ = 21000012011509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21000012011988 and 21000012012006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000012012521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 500000285980 + ... + 500000286021.

It is an arithmetic number, because the mean of its divisors is an integer number (4000002288008).

Almost surely, 2^{21000012012021} is an apocalyptic number.

21000012012021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21000012012021 is a deficient number, since it is larger than the sum of its proper divisors (11000006292043).

21000012012021 is a wasteful number, since it uses less digits than its factorization.

21000012012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000000572011.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21000012012021 its reverse (12021021000012), we get a palindrome (33021033012033).

The spelling of 21000012012021 in words is "twenty-one trillion, twelve million, twelve thousand, twenty-one".