21059059 has 4 divisors (see below), whose sum is σ = 24067504. Its totient is φ = 18050616.

The previous prime is 21059057. The next prime is 21059063. The reversal of 21059059 is 95095012.

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

It is a cyclic number.

It is not a de Polignac number, because 21059059 - 2¹ = 21059057 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 21059059.

It is not an unprimeable number, because it can be changed into a prime (21059057) 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 3 ways as a sum of consecutive naturals, for example, 1504212 + ... + 1504225.

It is an arithmetic number, because the mean of its divisors is an integer number (6016876).

Almost surely, 2^21059059 is an apocalyptic number.

21059059 is a deficient number, since it is larger than the sum of its proper divisors (3008445).

21059059 is an equidigital number, since it uses as much as digits as its factorization.

21059059 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3008444.

The product of its (nonzero) digits is 4050, while the sum is 31.

The square root of 21059059 is about 4589.0150359309. The cubic root of 21059059 is about 276.1508093756.

The spelling of 21059059 in words is "twenty-one million, fifty-nine thousand, fifty-nine".