11956621813 has 8 divisors (see below), whose sum is σ = 12190557600. Its totient is φ = 11723728848.

The previous prime is 11956621811. The next prime is 11956621837. The reversal of 11956621813 is 31812665911.

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 11956621813 - 2¹ = 11956621811 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11956621813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11956621811) 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, 237531 + ... + 283432.

It is an arithmetic number, because the mean of its divisors is an integer number (1523819700).

Almost surely, 2^11956621813 is an apocalyptic number.

It is an amenable number.

11956621813 is a deficient number, since it is larger than the sum of its proper divisors (233935787).

11956621813 is an equidigital number, since it uses as much as digits as its factorization.

11956621813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521411.

The product of its digits is 77760, while the sum is 43.

The spelling of 11956621813 in words is "eleven billion, nine hundred fifty-six million, six hundred twenty-one thousand, eight hundred thirteen".