21012033021 has 8 divisors (see below), whose sum is σ = 32018336064. Its totient is φ = 12006876000.

The previous prime is 21012033013. The next prime is 21012033059. The reversal of 21012033021 is 12033021012.

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

It is not a de Polignac number, because 21012033021 - 2³ = 21012033013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012033421) 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, 500286480 + ... + 500286521.

It is an arithmetic number, because the mean of its divisors is an integer number (4002292008).

Almost surely, 2^21012033021 is an apocalyptic number.

21012033021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21012033021 is a deficient number, since it is larger than the sum of its proper divisors (11006303043).

21012033021 is a wasteful number, since it uses less digits than its factorization.

21012033021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000573011.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21012033021 its reverse (12033021012), we get a palindrome (33045054033).

The spelling of 21012033021 in words is "twenty-one billion, twelve million, thirty-three thousand, twenty-one".