21002001212 has 24 divisors (see below), whose sum is σ = 39864636000. Its totient is φ = 9642237440.

The previous prime is 21002001203. The next prime is 21002001217. The reversal of 21002001212 is 21210020012.

It is a happy number.

It is a super-3 number, since 3×21002001212³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002001193 and 21002001202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002001217) 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, 3763712 + ... + 3769287.

It is an arithmetic number, because the mean of its divisors is an integer number (1661026500).

Almost surely, 2^21002001212 is an apocalyptic number.

It is an amenable number.

21002001212 is a deficient number, since it is larger than the sum of its proper divisors (18862634788).

21002001212 is a wasteful number, since it uses less digits than its factorization.

21002001212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7533061 (or 7533059 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21002001212 its reverse (21210020012), we get a palindrome (42212021224).

The spelling of 21002001212 in words is "twenty-one billion, two million, one thousand, two hundred twelve".