216821253586 has 8 divisors (see below), whose sum is σ = 371693577600. Its totient is φ = 92923394388.

The previous prime is 216821253581. The next prime is 216821253587. The reversal of 216821253586 is 685352128612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×216821253586² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (216821253581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7743616186 + ... + 7743616213.

It is an arithmetic number, because the mean of its divisors is an integer number (46461697200).

Almost surely, 2^216821253586 is an apocalyptic number.

216821253586 is a deficient number, since it is larger than the sum of its proper divisors (154872324014).

216821253586 is a wasteful number, since it uses less digits than its factorization.

216821253586 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15487232408.

The product of its digits is 1382400, while the sum is 49.

The spelling of 216821253586 in words is "two hundred sixteen billion, eight hundred twenty-one million, two hundred fifty-three thousand, five hundred eighty-six".