1020212121 has 4 divisors (see below), whose sum is σ = 1360282832. Its totient is φ = 680141412.

The previous prime is 1020212119. The next prime is 1020212161. The reversal of 1020212121 is 1212120201.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1212120201 = 3 ⋅404040067.

It is not a de Polignac number, because 1020212121 - 2¹ = 1020212119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020212097 and 1020212106.

It is not an unprimeable number, because it can be changed into a prime (1020212161) 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, 170035351 + ... + 170035356.

It is an arithmetic number, because the mean of its divisors is an integer number (340070708).

Almost surely, 2^1020212121 is an apocalyptic number.

It is an amenable number.

1020212121 is a deficient number, since it is larger than the sum of its proper divisors (340070711).

1020212121 is an equidigital number, since it uses as much as digits as its factorization.

1020212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340070710.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 1020212121 is about 31940.7595557776. The cubic root of 1020212121 is about 1006.6924844019.

Adding to 1020212121 its reverse (1212120201), we get a palindrome (2232332322).

The spelling of 1020212121 in words is "one billion, twenty million, two hundred twelve thousand, one hundred twenty-one".