201231545 has 4 divisors (see below), whose sum is σ = 241477860. Its totient is φ = 160985232.

The previous prime is 201231517. The next prime is 201231553. The reversal of 201231545 is 545132102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 545132102 = 2 ⋅272566051.

It can be written as a sum of positive squares in 2 ways, for example, as 123721129 + 77510416 = 11123^2 + 8804^2 .

It is a cyclic number.

It is not a de Polignac number, because 201231545 - 2²² = 197037241 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 201231545.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20123150 + ... + 20123159.

It is an arithmetic number, because the mean of its divisors is an integer number (60369465).

Almost surely, 2^201231545 is an apocalyptic number.

It is an amenable number.

201231545 is a deficient number, since it is larger than the sum of its proper divisors (40246315).

201231545 is an equidigital number, since it uses as much as digits as its factorization.

201231545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40246314.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 201231545 is about 14185.6104909165. The cubic root of 201231545 is about 586.0014453637.

Adding to 201231545 its reverse (545132102), we get a palindrome (746363647).

The spelling of 201231545 in words is "two hundred one million, two hundred thirty-one thousand, five hundred forty-five".