11648538721 has 8 divisors (see below), whose sum is σ = 12078055080. Its totient is φ = 11220878592.

The previous prime is 11648538689. The next prime is 11648538751. The reversal of 11648538721 is 12783584611.

It can be written as a sum of positive squares in 4 ways, for example, as 2944581696 + 8703957025 = 54264^2 + 93295^2 .

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

It is not a de Polignac number, because 11648538721 - 2⁵ = 11648538689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11648538751) 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, 451270 + ... + 476383.

It is an arithmetic number, because the mean of its divisors is an integer number (1509756885).

Almost surely, 2^11648538721 is an apocalyptic number.

It is an amenable number.

11648538721 is a deficient number, since it is larger than the sum of its proper divisors (429516359).

11648538721 is an equidigital number, since it uses as much as digits as its factorization.

11648538721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928115.

The product of its digits is 322560, while the sum is 46.

The spelling of 11648538721 in words is "eleven billion, six hundred forty-eight million, five hundred thirty-eight thousand, seven hundred twenty-one".