11521720543 has 8 divisors (see below), whose sum is σ = 11654400512. Its totient is φ = 11389696416.

The previous prime is 11521720537. The next prime is 11521720559. The reversal of 11521720543 is 34502712511.

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 11521720543 - 2⁹ = 11521720031 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11521720513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 128580 + ... + 198937.

It is an arithmetic number, because the mean of its divisors is an integer number (1456800064).

Almost surely, 2^11521720543 is an apocalyptic number.

11521720543 is a deficient number, since it is larger than the sum of its proper divisors (132679969).

11521720543 is a wasteful number, since it uses less digits than its factorization.

11521720543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327921.

The product of its (nonzero) digits is 8400, while the sum is 31.

The spelling of 11521720543 in words is "eleven billion, five hundred twenty-one million, seven hundred twenty thousand, five hundred forty-three".