21102441021 has 6 divisors (see below), whose sum is σ = 30481303710. Its totient is φ = 14068294008.

The previous prime is 21102441007. The next prime is 21102441079. The reversal of 21102441021 is 12014420112.

21102441021 is a `hidden beast` number, since 211 + 0 + 24 + 410 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20675564100 + 426876921 = 143790^2 + 20661^2 .

It is not a de Polignac number, because 21102441021 - 2¹³ = 21102432829 is a prime.

It is a super-3 number, since 3×21102441021³ (a number of 32 digits) contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21102440985 and 21102441003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102442021) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1172357826 + ... + 1172357843.

It is an arithmetic number, because the mean of its divisors is an integer number (5080217285).

Almost surely, 2^21102441021 is an apocalyptic number.

It is an amenable number.

21102441021 is a deficient number, since it is larger than the sum of its proper divisors (9378862689).

21102441021 is a wasteful number, since it uses less digits than its factorization.

21102441021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2344715675 (or 2344715672 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21102441021 its reverse (12014420112), we get a palindrome (33116861133).

The spelling of 21102441021 in words is "twenty-one billion, one hundred two million, four hundred forty-one thousand, twenty-one".