21001023212 has 12 divisors (see below), whose sum is σ = 39578851536. Its totient is φ = 9692779920.

The previous prime is 21001023193. The next prime is 21001023269. The reversal of 21001023212 is 21232010012.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201932864 + ... + 201932967.

It is an arithmetic number, because the mean of its divisors is an integer number (3298237628).

Almost surely, 2^21001023212 is an apocalyptic number.

It is an amenable number.

21001023212 is a deficient number, since it is larger than the sum of its proper divisors (18577828324).

21001023212 is a wasteful number, since it uses less digits than its factorization.

21001023212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403865848 (or 403865846 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21001023212 its reverse (21232010012), we get a palindrome (42233033224).

The spelling of 21001023212 in words is "twenty-one billion, one million, twenty-three thousand, two hundred twelve".