216821128612 has 48 divisors (see below), whose sum is σ = 461347548480. Its totient is φ = 87875712000.

The previous prime is 216821128609. The next prime is 216821128649.

216821128612 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×216821128612² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7613889 + ... + 7642312.

It is an arithmetic number, because the mean of its divisors is an integer number (9611407260).

Almost surely, 2^216821128612 is an apocalyptic number.

216821128612 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

216821128612 is an abundant number, since it is smaller than the sum of its proper divisors (244526419868).

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

216821128612 is a wasteful number, since it uses less digits than its factorization.

216821128612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15256252 (or 15256250 counting only the distinct ones).

The product of its digits is 36864, while the sum is 40.

The spelling of 216821128612 in words is "two hundred sixteen billion, eight hundred twenty-one million, one hundred twenty-eight thousand, six hundred twelve".