216400431 has 16 divisors (see below), whose sum is σ = 316594656. Its totient is φ = 130655616.

The previous prime is 216400427. The next prime is 216400447. The reversal of 216400431 is 134004612.

It is not a de Polignac number, because 216400431 - 2² = 216400427 is a prime.

It is a super-2 number, since 2×216400431² = 93658293073971522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 216400398 and 216400407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216400411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50280 + ... + 54413.

It is an arithmetic number, because the mean of its divisors is an integer number (19787166).

Almost surely, 2^216400431 is an apocalyptic number.

216400431 is a deficient number, since it is larger than the sum of its proper divisors (100194225).

216400431 is a wasteful number, since it uses less digits than its factorization.

216400431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104762.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 216400431 is about 14710.5550880992. Note that the first 3 decimals coincide. The cubic root of 216400431 is about 600.3705405635.

The spelling of 216400431 in words is "two hundred sixteen million, four hundred thousand, four hundred thirty-one".