216403641 has 12 divisors (see below), whose sum is σ = 312958932. Its totient is φ = 144095616.

The previous prime is 216403633. The next prime is 216403697. The reversal of 216403641 is 146304612.

216403641 is a `hidden beast` number, since 2 + 16 + 4 + 0 + 3 + 641 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 164865600 + 51538041 = 12840^2 + 7179^2 .

It is not a de Polignac number, because 216403641 - 2³ = 216403633 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (216403601) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6316 + ... + 21741.

It is an arithmetic number, because the mean of its divisors is an integer number (26079911).

Almost surely, 2^216403641 is an apocalyptic number.

It is an amenable number.

216403641 is a deficient number, since it is larger than the sum of its proper divisors (96555291).

216403641 is a wasteful number, since it uses less digits than its factorization.

216403641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28920 (or 28917 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 216403641 is about 14710.6641930268. The cubic root of 216403641 is about 600.3735091033.

It can be divided in two parts, 21640 and 3641, that added together give a square (25281 = 159²).

The spelling of 216403641 in words is "two hundred sixteen million, four hundred three thousand, six hundred forty-one".