421102021 has 4 divisors (see below), whose sum is σ = 431372844. Its totient is φ = 410831200.

The previous prime is 421101979. The next prime is 421102037. The reversal of 421102021 is 120201124.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62188996 + 358913025 = 7886^2 + 18945^2 .

It is a cyclic number.

It is not a de Polignac number, because 421102021 - 2²⁷ = 286884293 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 421101992 and 421102010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421102081) 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, 5135350 + ... + 5135431.

It is an arithmetic number, because the mean of its divisors is an integer number (107843211).

Almost surely, 2^421102021 is an apocalyptic number.

421102021 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

421102021 is a deficient number, since it is larger than the sum of its proper divisors (10270823).

421102021 is a wasteful number, since it uses less digits than its factorization.

421102021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10270822.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 421102021 is about 20520.7704777379. The cubic root of 421102021 is about 749.5416583246.

Adding to 421102021 its reverse (120201124), we get a palindrome (541303145).

The spelling of 421102021 in words is "four hundred twenty-one million, one hundred two thousand, twenty-one".