21001022212 has 12 divisors (see below), whose sum is σ = 37194582096. Its totient is φ = 10373998760.

The previous prime is 21001022209. The next prime is 21001022219. The reversal of 21001022212 is 21222010012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21001022192 and 21001022201.

It is not an unprimeable number, because it can be changed into a prime (21001022219) 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, 31627714 + ... + 31628377.

It is an arithmetic number, because the mean of its divisors is an integer number (3099548508).

Almost surely, 2^21001022212 is an apocalyptic number.

It is an amenable number.

21001022212 is a deficient number, since it is larger than the sum of its proper divisors (16193559884).

21001022212 is a wasteful number, since it uses less digits than its factorization.

21001022212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63256178 (or 63256176 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21001022212 its reverse (21222010012), we get a palindrome (42223032224).

The spelling of 21001022212 in words is "twenty-one billion, one million, twenty-two thousand, two hundred twelve".