21215122151212 has 24 divisors (see below), whose sum is σ = 42884043708240. Its totient is φ = 9075988085760.

The previous prime is 21215122151191. The next prime is 21215122151219.

21215122151212 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (21215122151219) 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, 14181230637 + ... + 14181232132.

It is an arithmetic number, because the mean of its divisors is an integer number (1786835154510).

Almost surely, 2^{21215122151212} is an apocalyptic number.

21215122151212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21215122151212 is an abundant number, since it is smaller than the sum of its proper divisors (21668921557028).

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

21215122151212 is a wasteful number, since it uses less digits than its factorization.

21215122151212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28362462801 (or 28362462799 counting only the distinct ones).

The product of its digits is 1600, while the sum is 28.

It can be divided in two parts, 2121512 and 2151212, that added together give a palindrome (4272724).

The spelling of 21215122151212 in words is "twenty-one trillion, two hundred fifteen billion, one hundred twenty-two million, one hundred fifty-one thousand, two hundred twelve".