19921441 has 4 divisors (see below), whose sum is σ = 20248084. Its totient is φ = 19594800.

The previous prime is 19921439. The next prime is 19921453. The reversal of 19921441 is 14412991.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10336225 + 9585216 = 3215^2 + 3096^2 .

It is a cyclic number.

It is not a de Polignac number, because 19921441 - 2¹ = 19921439 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19921471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 163230 + ... + 163351.

It is an arithmetic number, because the mean of its divisors is an integer number (5062021).

Almost surely, 2^19921441 is an apocalyptic number.

It is an amenable number.

19921441 is a deficient number, since it is larger than the sum of its proper divisors (326643).

19921441 is an equidigital number, since it uses as much as digits as its factorization.

19921441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 326642.

The product of its digits is 2592, while the sum is 31.

The square root of 19921441 is about 4463.3441498500. The cubic root of 19921441 is about 271.0858920834.

The spelling of 19921441 in words is "nineteen million, nine hundred twenty-one thousand, four hundred forty-one".