21601445 has 8 divisors (see below), whose sum is σ = 26066040. Its totient is φ = 17184960.

The previous prime is 21601429. The next prime is 21601453. The reversal of 21601445 is 54410612.

It can be written as a sum of positive squares in 4 ways, for example, as 376996 + 21224449 = 614^2 + 4607^2 .

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

It is not a de Polignac number, because 21601445 - 2⁴ = 21601429 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21601445.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11030 + ... + 12839.

It is an arithmetic number, because the mean of its divisors is an integer number (3258255).

Almost surely, 2^21601445 is an apocalyptic number.

It is an amenable number.

21601445 is a deficient number, since it is larger than the sum of its proper divisors (4464595).

21601445 is a wasteful number, since it uses less digits than its factorization.

21601445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24055.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21601445 is about 4647.7354700972. The cubic root of 21601445 is about 278.5015401522.

The spelling of 21601445 in words is "twenty-one million, six hundred one thousand, four hundred forty-five".