231435561 has 32 divisors (see below), whose sum is σ = 373120000. Its totient is φ = 124649280.

The previous prime is 231435559. The next prime is 231435563. The reversal of 231435561 is 165534132.

It is an interprime number because it is at equal distance from previous prime (231435559) and next prime (231435563).

It is not a de Polignac number, because 231435561 - 2¹ = 231435559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231435563) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 82815 + ... + 85563.

It is an arithmetic number, because the mean of its divisors is an integer number (11660000).

Almost surely, 2^231435561 is an apocalyptic number.

231435561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

231435561 is a deficient number, since it is larger than the sum of its proper divisors (141684439).

231435561 is a wasteful number, since it uses less digits than its factorization.

231435561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2989.

The product of its digits is 10800, while the sum is 30.

The square root of 231435561 is about 15213.0063103911. The cubic root of 231435561 is about 613.9646456883.

Adding to 231435561 its reverse (165534132), we get a palindrome (396969693).

The spelling of 231435561 in words is "two hundred thirty-one million, four hundred thirty-five thousand, five hundred sixty-one".