1000320021 has 12 divisors (see below), whose sum is σ = 1445981472. Its totient is φ = 666383976.

The previous prime is 1000320019. The next prime is 1000320031. The reversal of 1000320021 is 1200230001.

It is a happy number.

It is not a de Polignac number, because 1000320021 - 2¹ = 1000320019 is a prime.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1000319985 and 1000320012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000320011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28351 + ... + 52956.

It is an arithmetic number, because the mean of its divisors is an integer number (120498456).

Almost surely, 2^1000320021 is an apocalyptic number.

It is an amenable number.

1000320021 is a deficient number, since it is larger than the sum of its proper divisors (445661451).

1000320021 is a wasteful number, since it uses less digits than its factorization.

1000320021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82680 (or 82677 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 1000320021 is about 31627.8361732193. The cubic root of 1000320021 is about 1000.1066622894.

Adding to 1000320021 its reverse (1200230001), we get a palindrome (2200550022).

The spelling of 1000320021 in words is "one billion, three hundred twenty thousand, twenty-one".