216021506 has 8 divisors (see below), whose sum is σ = 326178624.
Its totient is φ = 107295300.
The previous prime is 216021473. The next prime is 216021511. The reversal of 216021506 is 605120612.
It is a sphenic number, since it is the product of 3 distinct primes.
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, 357350 + ... + 357953.
It is an arithmetic number, because the mean of its divisors is an integer number (40772328).
Almost surely, 2216021506 is an apocalyptic number.
216021506 is a deficient number, since it is larger than the sum of its proper divisors (110157118).
216021506 is a wasteful number, since it uses less digits than its factorization.
216021506 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 715456.
The product of its (nonzero) digits is 720, while the sum is 23.
The square root of 216021506 is about 14697.6700874662.
The cubic root of 216021506 is about 600.0199123021.
The spelling of 216021506 in words is "two hundred sixteen million, twenty-one thousand, five hundred six".