21021201023 has 16 divisors (see below), whose sum is σ = 21466427136. Its totient is φ = 20580246720.

The previous prime is 21021201001. The next prime is 21021201043. The reversal of 21021201023 is 32010212012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21021201023 - 2¹² = 21021196927 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021200989 and 21021201007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021201043) 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, 9214643 + ... + 9216923.

It is an arithmetic number, because the mean of its divisors is an integer number (1341651696).

Almost surely, 2^21021201023 is an apocalyptic number.

21021201023 is a deficient number, since it is larger than the sum of its proper divisors (445226113).

21021201023 is a wasteful number, since it uses less digits than its factorization.

21021201023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3134.

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

Adding to 21021201023 its reverse (32010212012), we get a palindrome (53031413035).

The spelling of 21021201023 in words is "twenty-one billion, twenty-one million, two hundred one thousand, twenty-three".