11504121661 has 4 divisors (see below), whose sum is σ = 11504416000. Its totient is φ = 11503827324.

The previous prime is 11504121641. The next prime is 11504121677. The reversal of 11504121661 is 16612140511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11504121661 - 2¹⁹ = 11503597373 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 (11504121641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77571 + ... + 170368.

It is an arithmetic number, because the mean of its divisors is an integer number (2876104000).

Almost surely, 2^11504121661 is an apocalyptic number.

It is an amenable number.

11504121661 is a deficient number, since it is larger than the sum of its proper divisors (294339).

11504121661 is an equidigital number, since it uses as much as digits as its factorization.

11504121661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294338.

The product of its (nonzero) digits is 1440, while the sum is 28.

The spelling of 11504121661 in words is "eleven billion, five hundred four million, one hundred twenty-one thousand, six hundred sixty-one".