216406451 has 4 divisors (see below), whose sum is σ = 222255312. Its totient is φ = 210557592.

The previous prime is 216406441. The next prime is 216406483. The reversal of 216406451 is 154604612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216406451 - 2⁶ = 216406387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216406441) 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, 2924375 + ... + 2924448.

It is an arithmetic number, because the mean of its divisors is an integer number (55563828).

Almost surely, 2^216406451 is an apocalyptic number.

216406451 is a deficient number, since it is larger than the sum of its proper divisors (5848861).

216406451 is an equidigital number, since it uses as much as digits as its factorization.

216406451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5848860.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 216406451 is about 14710.7597016606. The cubic root of 216406451 is about 600.3761077076.

The spelling of 216406451 in words is "two hundred sixteen million, four hundred six thousand, four hundred fifty-one".