1020421205 has 4 divisors (see below), whose sum is σ = 1224505452. Its totient is φ = 816336960.

The previous prime is 1020421177. The next prime is 1020421219. The reversal of 1020421205 is 5021240201.

1020421205 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: 5021240201 = 10429 ⋅481469.

It can be written as a sum of positive squares in 2 ways, for example, as 456548689 + 563872516 = 21367^2 + 23746^2 .

It is not a de Polignac number, because 1020421205 - 2²⁴ = 1003643989 is a prime.

It is a super-2 number, since 2×1020421205² = 2082518871227304050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102042116 + ... + 102042125.

It is an arithmetic number, because the mean of its divisors is an integer number (306126363).

Almost surely, 2^1020421205 is an apocalyptic number.

It is an amenable number.

1020421205 is a deficient number, since it is larger than the sum of its proper divisors (204084247).

1020421205 is an equidigital number, since it uses as much as digits as its factorization.

1020421205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204084246.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 1020421205 is about 31944.0323847820. The cubic root of 1020421205 is about 1006.7612507920.

Adding to 1020421205 its reverse (5021240201), we get a palindrome (6041661406).

The spelling of 1020421205 in words is "one billion, twenty million, four hundred twenty-one thousand, two hundred five".