11903915521 has 4 divisors (see below), whose sum is σ = 11939879344. Its totient is φ = 11867951700.

The previous prime is 11903915497. The next prime is 11903915603. The reversal of 11903915521 is 12551930911.

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 11903915521 - 2¹⁹ = 11903391233 is a prime.

It is a super-2 number, since 2×11903915521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11903913521) 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, 17981415 + ... + 17982076.

It is an arithmetic number, because the mean of its divisors is an integer number (2984969836).

Almost surely, 2^11903915521 is an apocalyptic number.

It is an amenable number.

11903915521 is a deficient number, since it is larger than the sum of its proper divisors (35963823).

11903915521 is an equidigital number, since it uses as much as digits as its factorization.

11903915521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35963822.

The product of its (nonzero) digits is 12150, while the sum is 37.

The spelling of 11903915521 in words is "eleven billion, nine hundred three million, nine hundred fifteen thousand, five hundred twenty-one".