21000021120121 has 8 divisors (see below), whose sum is σ = 21913380788544. Its totient is φ = 20086687724400.

The previous prime is 21000021120059. The next prime is 21000021120161. The reversal of 21000021120121 is 12102112000012.

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

It is a cyclic number.

It is not a de Polignac number, because 21000021120121 - 2³⁷ = 20862582166649 is a prime.

It is a super-2 number, since 2×21000021120121² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21000021120161) 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, 4926055 + ... + 8140396.

It is an arithmetic number, because the mean of its divisors is an integer number (2739172598568).

Almost surely, 2^{21000021120121} is an apocalyptic number.

It is an amenable number.

21000021120121 is a deficient number, since it is larger than the sum of its proper divisors (913359668423).

21000021120121 is a wasteful number, since it uses less digits than its factorization.

21000021120121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13136351.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21000021120121 its reverse (12102112000012), we get a palindrome (33102133120133).

The spelling of 21000021120121 in words is "twenty-one trillion, twenty-one million, one hundred twenty thousand, one hundred twenty-one".