216443451 has 16 divisors (see below), whose sum is σ = 338733824. Its totient is φ = 120338784.

The previous prime is 216443449. The next prime is 216443471. The reversal of 216443451 is 154344612.

It is not a de Polignac number, because 216443451 - 2¹ = 216443449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216443401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138505 + ... + 140058.

It is an arithmetic number, because the mean of its divisors is an integer number (21170864).

Almost surely, 2^216443451 is an apocalyptic number.

216443451 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

216443451 is a deficient number, since it is larger than the sum of its proper divisors (122290373).

216443451 is a wasteful number, since it uses less digits than its factorization.

216443451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278610.

The product of its digits is 11520, while the sum is 30.

The square root of 216443451 is about 14712.0172308219. The cubic root of 216443451 is about 600.4103221068.

The spelling of 216443451 in words is "two hundred sixteen million, four hundred forty-three thousand, four hundred fifty-one".