21011012204 has 36 divisors (see below), whose sum is σ = 45503149104. Its totient is φ = 8312046912.

The previous prime is 21011012177. The next prime is 21011012273. The reversal of 21011012204 is 40221011012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2215367 + ... + 2224830.

It is an arithmetic number, because the mean of its divisors is an integer number (1263976364).

Almost surely, 2^21011012204 is an apocalyptic number.

It is an amenable number.

21011012204 is an abundant number, since it is smaller than the sum of its proper divisors (24492136900).

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

21011012204 is a wasteful number, since it uses less digits than its factorization.

21011012204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4440234 (or 4440219 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21011012204 its reverse (40221011012), we get a palindrome (61232023216).

The spelling of 21011012204 in words is "twenty-one billion, eleven million, twelve thousand, two hundred four".