21395545 has 8 divisors (see below), whose sum is σ = 25717896. Its totient is φ = 17087616.

The previous prime is 21395527. The next prime is 21395551. The reversal of 21395545 is 54559312.

It can be written as a sum of positive squares in 4 ways, for example, as 207936 + 21187609 = 456^2 + 4603^2 .

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 21395545 - 2⁵ = 21395513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21395545.

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, 12 + ... + 6541.

It is an arithmetic number, because the mean of its divisors is an integer number (3214737).

Almost surely, 2^21395545 is an apocalyptic number.

It is an amenable number.

21395545 is a deficient number, since it is larger than the sum of its proper divisors (4322351).

21395545 is an equidigital number, since it uses as much as digits as its factorization.

21395545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7211.

The product of its digits is 27000, while the sum is 34.

The square root of 21395545 is about 4625.5318613107. The cubic root of 21395545 is about 277.6138428554.

The spelling of 21395545 in words is "twenty-one million, three hundred ninety-five thousand, five hundred forty-five".