21300149 has 4 divisors (see below), whose sum is σ = 22938636. Its totient is φ = 19661664.

The previous prime is 21300143. The next prime is 21300173. The reversal of 21300149 is 94100312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13359025 + 7941124 = 3655^2 + 2818^2 .

It is a cyclic number.

It is not a de Polignac number, because 21300149 - 2²⁴ = 4522933 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 21300149.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21300143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 819224 + ... + 819249.

It is an arithmetic number, because the mean of its divisors is an integer number (5734659).

Almost surely, 2^21300149 is an apocalyptic number.

It is an amenable number.

21300149 is a deficient number, since it is larger than the sum of its proper divisors (1638487).

21300149 is a wasteful number, since it uses less digits than its factorization.

21300149 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1638486.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 21300149 is about 4615.2084459968. The cubic root of 21300149 is about 277.2006305395.

The spelling of 21300149 in words is "twenty-one million, three hundred thousand, one hundred forty-nine".