21030401 has 4 divisors (see below), whose sum is σ = 24034752. Its totient is φ = 18026052.

The previous prime is 21030389. The next prime is 21030403. The reversal of 21030401 is 10403012.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 21030401 - 2⁶ = 21030337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21030403) 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, 1502165 + ... + 1502178.

It is an arithmetic number, because the mean of its divisors is an integer number (6008688).

Almost surely, 2^21030401 is an apocalyptic number.

It is an amenable number.

21030401 is a deficient number, since it is larger than the sum of its proper divisors (3004351).

21030401 is an equidigital number, since it uses as much as digits as its factorization.

21030401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3004350.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21030401 is about 4585.8915163793. The cubic root of 21030401 is about 276.0254868643.

Adding to 21030401 its reverse (10403012), we get a palindrome (31433413).

The spelling of 21030401 in words is "twenty-one million, thirty thousand, four hundred one".