21212864285 has 4 divisors (see below), whose sum is σ = 25455437148. Its totient is φ = 16970291424.

The previous prime is 21212864269. The next prime is 21212864293. The reversal of 21212864285 is 58246821212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13964385241 + 7248479044 = 118171^2 + 85138^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212864285 - 2⁴ = 21212864269 is a prime.

It is a super-2 number, since 2×21212864285² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2121286424 + ... + 2121286433.

It is an arithmetic number, because the mean of its divisors is an integer number (6363859287).

Almost surely, 2^21212864285 is an apocalyptic number.

It is an amenable number.

21212864285 is a deficient number, since it is larger than the sum of its proper divisors (4242572863).

21212864285 is an equidigital number, since it uses as much as digits as its factorization.

21212864285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4242572862.

The product of its digits is 122880, while the sum is 41.

The spelling of 21212864285 in words is "twenty-one billion, two hundred twelve million, eight hundred sixty-four thousand, two hundred eighty-five".