21141745 has 4 divisors (see below), whose sum is σ = 25370100. Its totient is φ = 16913392.

The previous prime is 21141733. The next prime is 21141751. The reversal of 21141745 is 54714112.

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 13256881 + 7884864 = 3641^2 + 2808^2 .

It is a cyclic number.

It is not a de Polignac number, because 21141745 - 2⁵ = 21141713 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2114170 + ... + 2114179.

It is an arithmetic number, because the mean of its divisors is an integer number (6342525).

Almost surely, 2^21141745 is an apocalyptic number.

It is an amenable number.

21141745 is a deficient number, since it is larger than the sum of its proper divisors (4228355).

21141745 is an equidigital number, since it uses as much as digits as its factorization.

21141745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4228354.

The product of its digits is 1120, while the sum is 25.

The square root of 21141745 is about 4598.0153327278. The cubic root of 21141745 is about 276.5117622884.

Adding to 21141745 its reverse (54714112), we get a palindrome (75855857).

The spelling of 21141745 in words is "twenty-one million, one hundred forty-one thousand, seven hundred forty-five".