21221021012 has 12 divisors (see below), whose sum is σ = 37196785920. Its totient is φ = 10593367896.

The previous prime is 21221021011. The next prime is 21221021021. The reversal of 21221021012 is 21012012212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221021011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4282868 + ... + 4287819.

It is an arithmetic number, because the mean of its divisors is an integer number (3099732160).

Almost surely, 2^21221021012 is an apocalyptic number.

It is an amenable number.

21221021012 is a deficient number, since it is larger than the sum of its proper divisors (15975764908).

21221021012 is a wasteful number, since it uses less digits than its factorization.

21221021012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8571310 (or 8571308 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21221021012 its reverse (21012012212), we get a palindrome (42233033224).

The spelling of 21221021012 in words is "twenty-one billion, two hundred twenty-one million, twenty-one thousand, twelve".