216440425 has 12 divisors (see below), whose sum is σ = 268643520. Its totient is φ = 172986320.

The previous prime is 216440407. The next prime is 216440431. The reversal of 216440425 is 524044612.

It is not a de Polignac number, because 216440425 - 2⁷ = 216440297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216440393 and 216440402.

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, 27036 + ... + 34114.

It is an arithmetic number, because the mean of its divisors is an integer number (22386960).

Almost surely, 2^216440425 is an apocalyptic number.

216440425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

216440425 is a deficient number, since it is larger than the sum of its proper divisors (52203095).

216440425 is a wasteful number, since it uses less digits than its factorization.

216440425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8312 (or 8307 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 28.

The square root of 216440425 is about 14711.9143893648. The cubic root of 216440425 is about 600.4075240701.

It can be divided in two parts, 21 and 6440425, that added together give a palindrome (6440446).

The spelling of 216440425 in words is "two hundred sixteen million, four hundred forty thousand, four hundred twenty-five".