21110001210 has 48 divisors (see below), whose sum is σ = 55371746664. Its totient is φ = 5579513856.

The previous prime is 21110001181. The next prime is 21110001287. The reversal of 21110001210 is 1210001112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3795915321 + 17314085889 = 61611^2 + 131583^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21110001192 and 21110001201.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1027687 + ... + 1048026.

Almost surely, 2^21110001210 is an apocalyptic number.

21110001210 is an abundant number, since it is smaller than the sum of its proper divisors (34261745454).

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

21110001210 is a wasteful number, since it uses less digits than its factorization.

21110001210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2075839 (or 2075836 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21110001210 its reverse (1210001112), we get a palindrome (22320002322).

The spelling of 21110001210 in words is "twenty-one billion, one hundred ten million, one thousand, two hundred ten".