21046401 has 6 divisors (see below), whose sum is σ = 30400370. Its totient is φ = 14030928.

The previous prime is 21046387. The next prime is 21046409. The reversal of 21046401 is 10464012.

21046401 is a `hidden beast` number, since 21 + 0 + 4 + 640 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20657025 + 389376 = 4545^2 + 624^2 .

It is not a de Polignac number, because 21046401 - 2⁷ = 21046273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21046409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1169236 + ... + 1169253.

Almost surely, 2^21046401 is an apocalyptic number.

It is an amenable number.

21046401 is a deficient number, since it is larger than the sum of its proper divisors (9353969).

21046401 is a wasteful number, since it uses less digits than its factorization.

21046401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2338495 (or 2338492 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21046401 is about 4587.6356655689. The cubic root of 21046401 is about 276.0954694934.

The spelling of 21046401 in words is "twenty-one million, forty-six thousand, four hundred one".