21210023210 has 8 divisors (see below), whose sum is σ = 38178041796. Its totient is φ = 8484009280.

The previous prime is 21210023143. The next prime is 21210023251. The reversal of 21210023210 is 1232001212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20922754609 + 287268601 = 144647^2 + 16949^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 1060501151 + ... + 1060501170.

Almost surely, 2^21210023210 is an apocalyptic number.

21210023210 is a deficient number, since it is larger than the sum of its proper divisors (16968018586).

21210023210 is a wasteful number, since it uses less digits than its factorization.

21210023210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2121002328.

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

Adding to 21210023210 its reverse (1232001212), we get a palindrome (22442024422).

It can be divided in two parts, 2121002 and 3210, that added together give a palindrome (2124212).

The spelling of 21210023210 in words is "twenty-one billion, two hundred ten million, twenty-three thousand, two hundred ten".