231406216209 has 27 divisors (see below), whose sum is σ = 388842385737. Its totient is φ = 132226350984.

The previous prime is 231406216207. The next prime is 231406216211. The reversal of 231406216209 is 902612604132.

It is a happy number.

The square root of 231406216209 is 481047.

It is a perfect power (a square), and thus also a powerful number.

231406216209 is a `hidden beast` number, since 2 + 3 + 1 + 4 + 0 + 6 + 21 + 620 + 9 = 666.

It is an interprime number because it is at equal distance from previous prime (231406216207) and next prime (231406216211).

It is not a de Polignac number, because 231406216209 - 2¹ = 231406216207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (231406216207) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 10090534 + ... + 10113440.

Almost surely, 2^231406216209 is an apocalyptic number.

231406216209 is the 481047-th square number.

231406216209 is the 240524-th centered octagonal number.

It is an amenable number.

231406216209 is a deficient number, since it is larger than the sum of its proper divisors (157436169528).

231406216209 is an frugal number, since it uses more digits than its factorization.

231406216209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45834 (or 22917 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

Multiplying 231406216209 by its sum of digits (36), we get a square (8330623783524 = 2886282²).

The spelling of 231406216209 in words is "two hundred thirty-one billion, four hundred six million, two hundred sixteen thousand, two hundred nine".