11821819 has 8 divisors (see below), whose sum is σ = 12846080. Its totient is φ = 10837800.

The previous prime is 11821787. The next prime is 11821841. The reversal of 11821819 is 91812811.

11821819 = T₄₅₇ + T₄₅₈ + ... + T₅₄₉.

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 11821819 - 2⁵ = 11821787 is a prime.

It is a super-2 number, since 2×11821819² = 279510808937522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11821519) 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, 9447 + ... + 10624.

It is an arithmetic number, because the mean of its divisors is an integer number (1605760).

Almost surely, 2^11821819 is an apocalyptic number.

11821819 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

11821819 is a deficient number, since it is larger than the sum of its proper divisors (1024261).

11821819 is a wasteful number, since it uses less digits than its factorization.

11821819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20121.

The product of its digits is 1152, while the sum is 31.

The square root of 11821819 is about 3438.2872189507. The cubic root of 11821819 is about 227.8040470375.

The spelling of 11821819 in words is "eleven million, eight hundred twenty-one thousand, eight hundred nineteen".