21002100010 has 16 divisors (see below), whose sum is σ = 37827304200. Its totient is φ = 8395612416.

The previous prime is 21002100001. The next prime is 21002100011. The reversal of 21002100010 is 1000120012.

It can be written as a sum of positive squares in 4 ways, for example, as 20976018561 + 26081449 = 144831^2 + 5107^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21002099966 and 21002100002.

It is not an unprimeable number, because it can be changed into a prime (21002100011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 636555 + ... + 668734.

Almost surely, 2^21002100010 is an apocalyptic number.

21002100010 is a deficient number, since it is larger than the sum of its proper divisors (16825204190).

21002100010 is a wasteful number, since it uses less digits than its factorization.

21002100010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1306905.

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 21002100010 its reverse (1000120012), we get a palindrome (22002220022).

The spelling of 21002100010 in words is "twenty-one billion, two million, one hundred thousand, ten".