11721819 has 8 divisors (see below), whose sum is σ = 15725632. Its totient is φ = 7766280.

The previous prime is 11721817. The next prime is 11721833. The reversal of 11721819 is 91812711.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 11721819 - 2¹ = 11721817 is a prime.

It is a super-2 number, since 2×11721819² = 274802081337522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11721811) 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, 11497 + ... + 12474.

It is an arithmetic number, because the mean of its divisors is an integer number (1965704).

Almost surely, 2^11721819 is an apocalyptic number.

11721819 is a deficient number, since it is larger than the sum of its proper divisors (4003813).

11721819 is a wasteful number, since it uses less digits than its factorization.

11721819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24137.

The product of its digits is 1008, while the sum is 30.

The square root of 11721819 is about 3423.7142112040. The cubic root of 11721819 is about 227.1599007932.

The spelling of 11721819 in words is "eleven million, seven hundred twenty-one thousand, eight hundred nineteen".