11661620403 has 4 divisors (see below), whose sum is σ = 15548827208. Its totient is φ = 7774413600.

The previous prime is 11661620371. The next prime is 11661620417. The reversal of 11661620403 is 30402616611.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 11661620403 - 2⁵ = 11661620371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11661620423) 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, 1943603398 + ... + 1943603403.

It is an arithmetic number, because the mean of its divisors is an integer number (3887206802).

Almost surely, 2^11661620403 is an apocalyptic number.

11661620403 is a deficient number, since it is larger than the sum of its proper divisors (3887206805).

11661620403 is an equidigital number, since it uses as much as digits as its factorization.

11661620403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3887206804.

The product of its (nonzero) digits is 5184, while the sum is 30.

The spelling of 11661620403 in words is "eleven billion, six hundred sixty-one million, six hundred twenty thousand, four hundred three".