21220021010 has 16 divisors (see below), whose sum is σ = 40442863896. Its totient is φ = 7988713728.

The previous prime is 21220021003. The next prime is 21220021033. The reversal of 21220021010 is 1012002212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21124587649 + 95433361 = 145343^2 + 9769^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21220020982 and 21220021000.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62411657 + ... + 62411996.

Almost surely, 2^21220021010 is an apocalyptic number.

21220021010 is a deficient number, since it is larger than the sum of its proper divisors (19222842886).

21220021010 is a wasteful number, since it uses less digits than its factorization.

21220021010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124823677.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21220021010 its reverse (1012002212), we get a palindrome (22232023222).

The spelling of 21220021010 in words is "twenty-one billion, two hundred twenty million, twenty-one thousand, ten".