21202420212 has 36 divisors (see below), whose sum is σ = 53649952356. Its totient is φ = 7060227840.

The previous prime is 21202420157. The next prime is 21202420243.

21202420212 is a `hidden beast` number, since 21 + 202 + 420 + 21 + 2 = 666.

21202420212 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 15746234256 + 5456185956 = 125484^2 + 73866^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×21202420212² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 266239 + ... + 336582.

Almost surely, 2^21202420212 is an apocalyptic number.

It is an amenable number.

21202420212 is an abundant number, since it is smaller than the sum of its proper divisors (32447532144).

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

21202420212 is a wasteful number, since it uses less digits than its factorization.

21202420212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603808 (or 603803 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The spelling of 21202420212 in words is "twenty-one billion, two hundred two million, four hundred twenty thousand, two hundred twelve".