21211101210 has 64 divisors (see below), whose sum is σ = 55751794560. Its totient is φ = 5132693760.

The previous prime is 21211101209. The next prime is 21211101257. The reversal of 21211101210 is 1210111212.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 437901 + ... + 483920.

It is an arithmetic number, because the mean of its divisors is an integer number (871121790).

Almost surely, 2^21211101210 is an apocalyptic number.

21211101210 is an abundant number, since it is smaller than the sum of its proper divisors (34540693350).

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

21211101210 is a wasteful number, since it uses less digits than its factorization.

21211101210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921903.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21211101210 its reverse (1210111212), we get a palindrome (22421212422).

The spelling of 21211101210 in words is "twenty-one billion, two hundred eleven million, one hundred one thousand, two hundred ten".