11997456438 has 64 divisors (see below), whose sum is σ = 26603728128. Its totient is φ = 3576376320.

The previous prime is 11997456431. The next prime is 11997456473. The reversal of 11997456438 is 83465479911.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11997456431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4318906 + ... + 4321682.

It is an arithmetic number, because the mean of its divisors is an integer number (415683252).

Almost surely, 2^11997456438 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11997456438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13301864064).

11997456438 is an abundant number, since it is smaller than the sum of its proper divisors (14606271690).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11997456438 is a wasteful number, since it uses less digits than its factorization.

11997456438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3837.

The product of its digits is 6531840, while the sum is 57.

The spelling of 11997456438 in words is "eleven billion, nine hundred ninety-seven million, four hundred fifty-six thousand, four hundred thirty-eight".