421220243 has 4 divisors (see below), whose sum is σ = 421263480. Its totient is φ = 421177008.

The previous prime is 421220231. The next prime is 421220249. The reversal of 421220243 is 342022124.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 421220243 - 2¹⁶ = 421154707 is a prime.

It is a super-2 number, since 2×421220243² = 354852986225958098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (421220249) 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, 623 + ... + 29031.

It is an arithmetic number, because the mean of its divisors is an integer number (105315870).

Almost surely, 2^421220243 is an apocalyptic number.

421220243 is a deficient number, since it is larger than the sum of its proper divisors (43237).

421220243 is a wasteful number, since it uses less digits than its factorization.

421220243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43236.

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 421220243 is about 20523.6508204559. The cubic root of 421220243 is about 749.6117949490.

Adding to 421220243 its reverse (342022124), we get a palindrome (763242367).

The spelling of 421220243 in words is "four hundred twenty-one million, two hundred twenty thousand, two hundred forty-three".