216309725 has 6 divisors (see below), whose sum is σ = 268224090. Its totient is φ = 173047760.

The previous prime is 216309713. The next prime is 216309767. The reversal of 216309725 is 527903612.

It can be written as a sum of positive squares in 3 ways, for example, as 1570009 + 214739716 = 1253^2 + 14654^2 .

It is not a de Polignac number, because 216309725 - 2⁸ = 216309469 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4326170 + ... + 4326219.

It is an arithmetic number, because the mean of its divisors is an integer number (44704015).

Almost surely, 2^216309725 is an apocalyptic number.

216309725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

216309725 is a deficient number, since it is larger than the sum of its proper divisors (51914365).

216309725 is an equidigital number, since it uses as much as digits as its factorization.

216309725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8652399 (or 8652394 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 35.

The square root of 216309725 is about 14707.4717405814. The cubic root of 216309725 is about 600.2866454429.

The spelling of 216309725 in words is "two hundred sixteen million, three hundred nine thousand, seven hundred twenty-five".