21554941 has 4 divisors (see below), whose sum is σ = 21961692. Its totient is φ = 21148192.

The previous prime is 21554927. The next prime is 21554947. The reversal of 21554941 is 14945512.

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 11758041 + 9796900 = 3429^2 + 3130^2 .

It is a cyclic number.

It is not a de Polignac number, because 21554941 - 2¹¹ = 21552893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554947) 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, 203296 + ... + 203401.

It is an arithmetic number, because the mean of its divisors is an integer number (5490423).

Almost surely, 2^21554941 is an apocalyptic number.

It is an amenable number.

21554941 is a deficient number, since it is larger than the sum of its proper divisors (406751).

21554941 is an equidigital number, since it uses as much as digits as its factorization.

21554941 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406750.

The product of its digits is 7200, while the sum is 31.

The square root of 21554941 is about 4642.7299081467. The cubic root of 21554941 is about 278.3015420998.

The spelling of 21554941 in words is "twenty-one million, five hundred fifty-four thousand, nine hundred forty-one".