11905421 has 8 divisors (see below), whose sum is σ = 13552704. Its totient is φ = 10352320.

The previous prime is 11905409. The next prime is 11905427. The reversal of 11905421 is 12450911.

It is a happy number.

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

It is not a de Polignac number, because 11905421 - 2¹⁰ = 11904397 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11905427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23276 + ... + 23781.

It is an arithmetic number, because the mean of its divisors is an integer number (1694088).

Almost surely, 2^11905421 is an apocalyptic number.

11905421 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11905421 is a deficient number, since it is larger than the sum of its proper divisors (1647283).

11905421 is a wasteful number, since it uses less digits than its factorization.

11905421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47091.

The product of its (nonzero) digits is 360, while the sum is 23.

The square root of 11905421 is about 3450.4233073639. The cubic root of 11905421 is about 228.3397839772.

Subtracting 11905421 from its reverse (12450911), we obtain a triangular number (545490 = T₁₀₄₄).

The spelling of 11905421 in words is "eleven million, nine hundred five thousand, four hundred twenty-one".