216403131 has 8 divisors (see below), whose sum is σ = 329757184. Its totient is φ = 123658920.

The previous prime is 216403097. The next prime is 216403139. The reversal of 216403131 is 131304612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 216403131 - 2¹³ = 216394939 is a prime.

It is a super-2 number, since 2×216403131² = 93660630213206322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 10304911 = 216403131 / (2 + 1 + 6 + 4 + 0 + 3 + 1 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216403098 and 216403107.

It is not an unprimeable number, because it can be changed into a prime (216403139) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5152435 + ... + 5152476.

It is an arithmetic number, because the mean of its divisors is an integer number (41219648).

Almost surely, 2^216403131 is an apocalyptic number.

216403131 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

216403131 is a deficient number, since it is larger than the sum of its proper divisors (113354053).

216403131 is a wasteful number, since it uses less digits than its factorization.

216403131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10304921.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 216403131 is about 14710.6468586531. The cubic root of 216403131 is about 600.3730374681.

Adding to 216403131 its reverse (131304612), we get a palindrome (347707743).

The spelling of 216403131 in words is "two hundred sixteen million, four hundred three thousand, one hundred thirty-one".