19421805 has 32 divisors (see below), whose sum is σ = 33755904. Its totient is φ = 9478656.

The previous prime is 19421791. The next prime is 19421807. The reversal of 19421805 is 50812491.

It is a happy number.

It is not a de Polignac number, because 19421805 - 2⁴ = 19421789 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19421807) 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, 26352 + ... + 27078.

It is an arithmetic number, because the mean of its divisors is an integer number (1054872).

Almost surely, 2^19421805 is an apocalyptic number.

19421805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19421805 is a deficient number, since it is larger than the sum of its proper divisors (14334099).

19421805 is a wasteful number, since it uses less digits than its factorization.

19421805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 885.

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 19421805 is about 4407.0176990795. The cubic root of 19421805 is about 268.8003705839.

The spelling of 19421805 in words is "nineteen million, four hundred twenty-one thousand, eight hundred five".