1243541521 has 8 divisors (see below), whose sum is σ = 1274513184. Its totient is φ = 1212600480.

The previous prime is 1243541503. The next prime is 1243541543. The reversal of 1243541521 is 1251453421.

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

It is a cyclic number.

It is not a de Polignac number, because 1243541521 - 2⁹ = 1243541009 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1243541521.

It is not an unprimeable number, because it can be changed into a prime (1243541561) 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 7 ways as a sum of consecutive naturals, for example, 89766 + ... + 102688.

It is an arithmetic number, because the mean of its divisors is an integer number (159314148).

Almost surely, 2^1243541521 is an apocalyptic number.

It is an amenable number.

1243541521 is a deficient number, since it is larger than the sum of its proper divisors (30971663).

1243541521 is a wasteful number, since it uses less digits than its factorization.

1243541521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15311.

The product of its digits is 4800, while the sum is 28.

The square root of 1243541521 is about 35263.8840883984. The cubic root of 1243541521 is about 1075.3588910949.

Adding to 1243541521 its reverse (1251453421), we get a palindrome (2494994942).

It can be divided in two parts, 12435 and 41521, that added together give a triangular number (53956 = T₃₂₈).

The spelling of 1243541521 in words is "one billion, two hundred forty-three million, five hundred forty-one thousand, five hundred twenty-one".