216521450 has 24 divisors (see below), whose sum is σ = 406649568. Its totient is φ = 85765680.

The previous prime is 216521449. The next prime is 216521507. The reversal of 216521450 is 54125612.

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15872 + ... + 26171.

It is an arithmetic number, because the mean of its divisors is an integer number (16943732).

Almost surely, 2^216521450 is an apocalyptic number.

216521450 is a deficient number, since it is larger than the sum of its proper divisors (190128118).

216521450 is a wasteful number, since it uses less digits than its factorization.

216521450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42158 (or 42153 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 216521450 is about 14714.6678521807. The cubic root of 216521450 is about 600.4824360625.

The spelling of 216521450 in words is "two hundred sixteen million, five hundred twenty-one thousand, four hundred fifty".