21046899 has 16 divisors (see below), whose sum is σ = 28980000. Its totient is φ = 13578240.

The previous prime is 21046897. The next prime is 21046903. The reversal of 21046899 is 99864012.

It is not a de Polignac number, because 21046899 - 2¹ = 21046897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21046897) 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 15 ways as a sum of consecutive naturals, for example, 16227 + ... + 17475.

It is an arithmetic number, because the mean of its divisors is an integer number (1811250).

Almost surely, 2^21046899 is an apocalyptic number.

21046899 is a deficient number, since it is larger than the sum of its proper divisors (7933101).

21046899 is a wasteful number, since it uses less digits than its factorization.

21046899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1430.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 21046899 is about 4587.6899415719. The cubic root of 21046899 is about 276.0976471335.

It can be divided in two parts, 21046 and 899, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21046899 in words is "twenty-one million, forty-six thousand, eight hundred ninety-nine".