21205450212 has 24 divisors (see below), whose sum is σ = 50816665536. Its totient is φ = 6877443168.

The previous prime is 21205450199. The next prime is 21205450247.

21205450212 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×21205450212² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23879568 + ... + 23880455.

It is an arithmetic number, because the mean of its divisors is an integer number (2117361064).

Almost surely, 2^21205450212 is an apocalyptic number.

It is an amenable number.

21205450212 is an abundant number, since it is smaller than the sum of its proper divisors (29611215324).

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

21205450212 is a wasteful number, since it uses less digits than its factorization.

21205450212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47760067 (or 47760065 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

The spelling of 21205450212 in words is "twenty-one billion, two hundred five million, four hundred fifty thousand, two hundred twelve".