21300145 has 8 divisors (see below), whose sum is σ = 25586280. Its totient is φ = 17022720.

The previous prime is 21300143. The next prime is 21300173. The reversal of 21300145 is 54100312.

It can be written as a sum of positive squares in 4 ways, for example, as 833569 + 20466576 = 913^2 + 4524^2 .

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

It is not a de Polignac number, because 21300145 - 2¹ = 21300143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21300143) 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, 6015 + ... + 8875.

It is an arithmetic number, because the mean of its divisors is an integer number (3198285).

Almost surely, 2^21300145 is an apocalyptic number.

It is an amenable number.

21300145 is a deficient number, since it is larger than the sum of its proper divisors (4286135).

21300145 is a wasteful number, since it uses less digits than its factorization.

21300145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4355.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21300145 is about 4615.2080126469. The cubic root of 21300145 is about 277.2006131875.

Adding to 21300145 its reverse (54100312), we get a palindrome (75400457).

The spelling of 21300145 in words is "twenty-one million, three hundred thousand, one hundred forty-five".