21201020012 has 24 divisors (see below), whose sum is σ = 37531680480. Its totient is φ = 10477765760.

The previous prime is 21201020003. The next prime is 21201020023. The reversal of 21201020012 is 21002010212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21201019975 and 21201020002.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1223513 + ... + 1240719.

It is an arithmetic number, because the mean of its divisors is an integer number (1563820020).

Almost surely, 2^21201020012 is an apocalyptic number.

It is an amenable number.

21201020012 is a deficient number, since it is larger than the sum of its proper divisors (16330660468).

21201020012 is a wasteful number, since it uses less digits than its factorization.

21201020012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20761 (or 20759 counting only the distinct ones).

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

Adding to 21201020012 its reverse (21002010212), we get a palindrome (42203030224).

It can be divided in two parts, 212010200 and 12, that added together give a palindrome (212010212).

The spelling of 21201020012 in words is "twenty-one billion, two hundred one million, twenty thousand, twelve".