21121222002101 has 16 divisors (see below), whose sum is σ = 24091644871728. Its totient is φ = 18343778918400.

The previous prime is 21121222002071. The next prime is 21121222002103. The reversal of 21121222002101 is 10120022212112.

It can be written as a sum of positive squares in 8 ways, for example, as 1641127534225 + 19480094467876 = 1281065^2 + 4413626^2 .

It is not a de Polignac number, because 21121222002101 - 2²² = 21121217807797 is a prime.

It is a super-2 number, since 2×21121222002101² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21121222002101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121222002103) 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, 14621240 + ... + 16000721.

It is an arithmetic number, because the mean of its divisors is an integer number (1505727804483).

Almost surely, 2^{21121222002101} is an apocalyptic number.

It is an amenable number.

21121222002101 is a deficient number, since it is larger than the sum of its proper divisors (2970422869627).

21121222002101 is a wasteful number, since it uses less digits than its factorization.

21121222002101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30625112.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21121222002101 its reverse (10120022212112), we get a palindrome (31241244214213).

The spelling of 21121222002101 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-two million, two thousand, one hundred one".