21111032021 has 8 divisors (see below), whose sum is σ = 22956989400. Its totient is φ = 19332200448.

The previous prime is 21111031999. The next prime is 21111032083. The reversal of 21111032021 is 12023011112.

It can be written as a sum of positive squares in 4 ways, for example, as 16643580100 + 4467451921 = 129010^2 + 66839^2 .

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

It is not a de Polignac number, because 21111032021 - 2⁶ = 21111031957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111031987 and 21111032005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111032521) 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, 16780796 + ... + 16782053.

It is an arithmetic number, because the mean of its divisors is an integer number (2869623675).

Almost surely, 2^21111032021 is an apocalyptic number.

It is an amenable number.

21111032021 is a deficient number, since it is larger than the sum of its proper divisors (1845957379).

21111032021 is a wasteful number, since it uses less digits than its factorization.

21111032021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33562903.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21111032021 its reverse (12023011112), we get a palindrome (33134043133).

The spelling of 21111032021 in words is "twenty-one billion, one hundred eleven million, thirty-two thousand, twenty-one".