21064849 has 8 divisors (see below), whose sum is σ = 23671872. Its totient is φ = 18598800.

The previous prime is 21064843. The next prime is 21064891. The reversal of 21064849 is 94846012.

21064849 = 102² + 103² + ... + 400².

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

It is a cyclic number.

It is not a de Polignac number, because 21064849 - 2¹¹ = 21062801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21064843) 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, 34927 + ... + 35524.

It is an arithmetic number, because the mean of its divisors is an integer number (2958984).

Almost surely, 2^21064849 is an apocalyptic number.

It is an amenable number.

21064849 is a deficient number, since it is larger than the sum of its proper divisors (2607023).

21064849 is a wasteful number, since it uses less digits than its factorization.

21064849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70487.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 21064849 is about 4589.6458469037. The cubic root of 21064849 is about 276.1761154552.

The spelling of 21064849 in words is "twenty-one million, sixty-four thousand, eight hundred forty-nine".