10021421 has 4 divisors (see below), whose sum is σ = 10037244. Its totient is φ = 10005600.

The previous prime is 10021411. The next prime is 10021423. The reversal of 10021421 is 12412001.

10021421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12412001 = 7 ⋅1773143.

It can be written as a sum of positive squares in 2 ways, for example, as 6817321 + 3204100 = 2611^2 + 1790^2 .

It is a cyclic number.

It is not a de Polignac number, because 10021421 - 2⁶ = 10021357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10021423) 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, 6920 + ... + 8241.

It is an arithmetic number, because the mean of its divisors is an integer number (2509311).

Almost surely, 2^10021421 is an apocalyptic number.

It is an amenable number.

10021421 is a deficient number, since it is larger than the sum of its proper divisors (15823).

10021421 is an equidigital number, since it uses as much as digits as its factorization.

10021421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15822.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 10021421 is about 3165.6628057960. The cubic root of 10021421 is about 215.5971931096.

Adding to 10021421 its reverse (12412001), we get a palindrome (22433422).

The spelling of 10021421 in words is "ten million, twenty-one thousand, four hundred twenty-one".