21020231021 has 8 divisors (see below), whose sum is σ = 21076773120. Its totient is φ = 20963737872.

The previous prime is 21020230981. The next prime is 21020231027. The reversal of 21020231021 is 12013202012.

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 a de Polignac number, because none of the positive numbers 2^k-21020231021 is a prime.

It is a super-2 number, since 2×21020231021² (a number of 21 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 = 21020230987 and 21020231005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020231027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 946976 + ... + 968918.

It is an arithmetic number, because the mean of its divisors is an integer number (2634596640).

Almost surely, 2^21020231021 is an apocalyptic number.

It is an amenable number.

21020231021 is a deficient number, since it is larger than the sum of its proper divisors (56542099).

21020231021 is a wasteful number, since it uses less digits than its factorization.

21020231021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24475.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21020231021 its reverse (12013202012), we get a palindrome (33033433033).

The spelling of 21020231021 in words is "twenty-one billion, twenty million, two hundred thirty-one thousand, twenty-one".