216400001 has 16 divisors (see below), whose sum is σ = 229338000. Its totient is φ = 203884800.

The previous prime is 216399983. The next prime is 216400003. The reversal of 216400001 is 100004612.

It can be written as a sum of positive squares in 8 ways, for example, as 74218225 + 142181776 = 8615^2 + 11924^2 .

It is a cyclic number.

It is not a de Polignac number, because 216400001 - 2¹⁴ = 216383617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216400003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 263171 + ... + 263991.

It is an arithmetic number, because the mean of its divisors is an integer number (14333625).

Almost surely, 2^216400001 is an apocalyptic number.

It is an amenable number.

216400001 is a deficient number, since it is larger than the sum of its proper divisors (12937999).

216400001 is a wasteful number, since it uses less digits than its factorization.

216400001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 216400001 is about 14710.5404727359. The cubic root of 216400001 is about 600.3701429064.

Adding to 216400001 its reverse (100004612), we get a palindrome (316404613).

The spelling of 216400001 in words is "two hundred sixteen million, four hundred thousand, one".