21123221010 has 16 divisors (see below), whose sum is σ = 50695730496. Its totient is φ = 5632858928.

The previous prime is 21123221003. The next prime is 21123221011. The reversal of 21123221010 is 1012232112.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is not an unprimeable number, because it can be changed into a prime (21123221011) 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, 352053654 + ... + 352053713.

It is an arithmetic number, because the mean of its divisors is an integer number (3168483156).

Almost surely, 2^21123221010 is an apocalyptic number.

21123221010 is an abundant number, since it is smaller than the sum of its proper divisors (29572509486).

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

21123221010 is a wasteful number, since it uses less digits than its factorization.

21123221010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 704107377.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21123221010 its reverse (1012232112), we get a palindrome (22135453122).

The spelling of 21123221010 in words is "twenty-one billion, one hundred twenty-three million, two hundred twenty-one thousand, ten".