216806425 has 12 divisors (see below), whose sum is σ = 293280336. Its totient is φ = 157677200.

The previous prime is 216806413. The next prime is 216806449. The reversal of 216806425 is 524608612.

It is not a de Polignac number, because 216806425 - 2²¹ = 214709273 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 393919 + ... + 394468.

It is an arithmetic number, because the mean of its divisors is an integer number (24440028).

Almost surely, 2^216806425 is an apocalyptic number.

216806425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

216806425 is a deficient number, since it is larger than the sum of its proper divisors (76473911).

216806425 is a wasteful number, since it uses less digits than its factorization.

216806425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788408 (or 788403 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 216806425 is about 14724.3480331049. The cubic root of 216806425 is about 600.7457624946.

The spelling of 216806425 in words is "two hundred sixteen million, eight hundred six thousand, four hundred twenty-five".