1020210021 has 24 divisors (see below), whose sum is σ = 1501063200. Its totient is φ = 667588896.

The previous prime is 1020210019. The next prime is 1020210047. The reversal of 1020210021 is 1200120201.

It is not a de Polignac number, because 1020210021 - 2¹ = 1020210019 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 1020209985 and 1020210012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020210221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 112930 + ... + 121628.

It is an arithmetic number, because the mean of its divisors is an integer number (62544300).

Almost surely, 2^1020210021 is an apocalyptic number.

It is an amenable number.

1020210021 is a deficient number, since it is larger than the sum of its proper divisors (480853179).

1020210021 is a wasteful number, since it uses less digits than its factorization.

1020210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8945 (or 8942 counting only the distinct ones).

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

The square root of 1020210021 is about 31940.7266824035. The cubic root of 1020210021 is about 1006.6917936776.

Adding to 1020210021 its reverse (1200120201), we get a palindrome (2220330222).

The spelling of 1020210021 in words is "one billion, twenty million, two hundred ten thousand, twenty-one".