21330012021 has 64 divisors (see below), whose sum is σ = 31088074752. Its totient is φ = 12973289472.

The previous prime is 21330012019. The next prime is 21330012023. The reversal of 21330012021 is 12021003312.

It is an interprime number because it is at equal distance from previous prime (21330012019) and next prime (21330012023).

It is not a de Polignac number, because 21330012021 - 2¹ = 21330012019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21330012023) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 33172326 + ... + 33172968.

It is an arithmetic number, because the mean of its divisors is an integer number (485751168).

Almost surely, 2^21330012021 is an apocalyptic number.

It is an amenable number.

21330012021 is a deficient number, since it is larger than the sum of its proper divisors (9758062731).

21330012021 is a wasteful number, since it uses less digits than its factorization.

21330012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 962.

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

Adding to 21330012021 its reverse (12021003312), we get a palindrome (33351015333).

The spelling of 21330012021 in words is "twenty-one billion, three hundred thirty million, twelve thousand, twenty-one".