11721838 has 4 divisors (see below), whose sum is σ = 17582760. Its totient is φ = 5860918.

The previous prime is 11721833. The next prime is 11721839. The reversal of 11721838 is 83812711.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11721833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2930458 + ... + 2930461.

It is an arithmetic number, because the mean of its divisors is an integer number (4395690).

Almost surely, 2^11721838 is an apocalyptic number.

11721838 is a deficient number, since it is larger than the sum of its proper divisors (5860922).

11721838 is an equidigital number, since it uses as much as digits as its factorization.

11721838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5860921.

The product of its digits is 2688, while the sum is 31.

The square root of 11721838 is about 3423.7169859672. The cubic root of 11721838 is about 227.1600235283.

The spelling of 11721838 in words is "eleven million, seven hundred twenty-one thousand, eight hundred thirty-eight".