21001021012111 has 8 divisors (see below), whose sum is σ = 25413000216480. Its totient is φ = 16942000144128.

The previous prime is 21001021012051. The next prime is 21001021012157. The reversal of 21001021012111 is 11121012010012.

It is a happy number.

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 21001021012111 - 2¹⁵ = 21001020979343 is a prime.

It is a super-2 number, since 2×21001021012111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001021012091 and 21001021012100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001021052111) 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, 88239583966 + ... + 88239584203.

It is an arithmetic number, because the mean of its divisors is an integer number (3176625027060).

Almost surely, 2^{21001021012111} is an apocalyptic number.

21001021012111 is a deficient number, since it is larger than the sum of its proper divisors (4411979204369).

21001021012111 is a wasteful number, since it uses less digits than its factorization.

21001021012111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176479168193.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21001021012111 its reverse (11121012010012), we get a palindrome (32122033022123).

The spelling of 21001021012111 in words is "twenty-one trillion, one billion, twenty-one million, twelve thousand, one hundred eleven".