21211210000 has 50 divisors (see below), whose sum is σ = 51354484742. Its totient is φ = 8484480000.

The previous prime is 21211209997. The next prime is 21211210021. The reversal of 21211210000 is 1211212.

It can be written as a sum of positive squares in 5 ways, for example, as 2198109456 + 19013100544 = 46884^2 + 137888^2 .

It is a tau number, because it is divible by the number of its divisors (50).

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1050561 + ... + 1070560.

Almost surely, 2^21211210000 is an apocalyptic number.

21211210000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21211210000 is an abundant number, since it is smaller than the sum of its proper divisors (30143274742).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21211210000 is an equidigital number, since it uses as much as digits as its factorization.

21211210000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2121149 (or 2121128 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21211210000 its reverse (1211212), we get a palindrome (21212421212).

It can be divided in two parts, 2121 and 1210000, that added together give a palindrome (1212121).

The spelling of 21211210000 in words is "twenty-one billion, two hundred eleven million, two hundred ten thousand".