21541445 has 8 divisors (see below), whose sum is σ = 25881336. Its totient is φ = 17212096.

The previous prime is 21541439. The next prime is 21541447. The reversal of 21541445 is 54414512.

It can be written as a sum of positive squares in 4 ways, for example, as 1623076 + 19918369 = 1274^2 + 4463^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21541445 - 2¹² = 21537349 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21541447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2939 + ... + 7191.

It is an arithmetic number, because the mean of its divisors is an integer number (3235167).

Almost surely, 2^21541445 is an apocalyptic number.

It is an amenable number.

21541445 is a deficient number, since it is larger than the sum of its proper divisors (4339891).

21541445 is a wasteful number, since it uses less digits than its factorization.

21541445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5271.

The product of its digits is 3200, while the sum is 26.

The square root of 21541445 is about 4641.2762253501. The cubic root of 21541445 is about 278.2434464985.

Adding to 21541445 its reverse (54414512), we get a palindrome (75955957).

The spelling of 21541445 in words is "twenty-one million, five hundred forty-one thousand, four hundred forty-five".