1020012021 has 20 divisors (see below), whose sum is σ = 1741397152. Its totient is φ = 582863688.

The previous prime is 1020012013. The next prime is 1020012107. The reversal of 1020012021 is 1202100201.

It is not a de Polignac number, because 1020012021 - 2³ = 1020012013 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020011994 and 1020012012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020012821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 898915 + ... + 900048.

Almost surely, 2^1020012021 is an apocalyptic number.

It is an amenable number.

1020012021 is a deficient number, since it is larger than the sum of its proper divisors (721385131).

1020012021 is an equidigital number, since it uses as much as digits as its factorization.

1020012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1798982 (or 1798973 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

The square root of 1020012021 is about 31937.6270408432. The cubic root of 1020012021 is about 1006.6266639928.

Adding to 1020012021 its reverse (1202100201), we get a palindrome (2222112222).

The spelling of 1020012021 in words is "one billion, twenty million, twelve thousand, twenty-one".