21049401 has 4 divisors (see below), whose sum is σ = 28065872. Its totient is φ = 14032932.

The previous prime is 21049387. The next prime is 21049493. The reversal of 21049401 is 10494012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21049401 - 2⁹ = 21048889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21049001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3508231 + ... + 3508236.

It is an arithmetic number, because the mean of its divisors is an integer number (7016468).

Almost surely, 2^21049401 is an apocalyptic number.

It is an amenable number.

21049401 is a deficient number, since it is larger than the sum of its proper divisors (7016471).

21049401 is an equidigital number, since it uses as much as digits as its factorization.

21049401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7016470.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21049401 is about 4587.9626197257. The cubic root of 21049401 is about 276.1085872874.

The spelling of 21049401 in words is "twenty-one million, forty-nine thousand, four hundred one".