21445355 has 16 divisors (see below), whose sum is σ = 26848800. Its totient is φ = 16423680.

The previous prime is 21445349. The next prime is 21445373. The reversal of 21445355 is 55354412.

It is not a de Polignac number, because 21445355 - 2¹⁴ = 21428971 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18431 + ... + 19559.

It is an arithmetic number, because the mean of its divisors is an integer number (1678050).

Almost surely, 2^21445355 is an apocalyptic number.

21445355 is a deficient number, since it is larger than the sum of its proper divisors (5403445).

21445355 is a wasteful number, since it uses less digits than its factorization.

21445355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1294.

The product of its digits is 12000, while the sum is 29.

The square root of 21445355 is about 4630.9129769409. The cubic root of 21445355 is about 277.8291092989.

Adding to 21445355 its reverse (55354412), we get a palindrome (76799767).

The spelling of 21445355 in words is "twenty-one million, four hundred forty-five thousand, three hundred fifty-five".