21004059 has 16 divisors (see below), whose sum is σ = 29030400. Its totient is φ = 13499616.

The previous prime is 21004057. The next prime is 21004073. The reversal of 21004059 is 95040012.

It is not a de Polignac number, because 21004059 - 2¹ = 21004057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21004057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8262 + ... + 10500.

It is an arithmetic number, because the mean of its divisors is an integer number (1814400).

Almost surely, 2^21004059 is an apocalyptic number.

21004059 is a deficient number, since it is larger than the sum of its proper divisors (8026341).

21004059 is a wasteful number, since it uses less digits than its factorization.

21004059 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2354.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 21004059 is about 4583.0185467659. The cubic root of 21004059 is about 275.9101918473.

The spelling of 21004059 in words is "twenty-one million, four thousand, fifty-nine".