1002000021 has 8 divisors (see below), whose sum is σ = 1457454624. Its totient is φ = 607272720.

The previous prime is 1002000001. The next prime is 1002000029. The reversal of 1002000021 is 1200002001.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1002000021 - 2⁵ = 1001999989 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1001999973 and 1002000009.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1002000029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15181786 + ... + 15181851.

It is an arithmetic number, because the mean of its divisors is an integer number (182181828).

Almost surely, 2^1002000021 is an apocalyptic number.

1002000021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1002000021 is a deficient number, since it is larger than the sum of its proper divisors (455454603).

1002000021 is a wasteful number, since it uses less digits than its factorization.

1002000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30363651.

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 1002000021 is about 31654.3839143964. The cubic root of 1002000021 is about 1000.6662297061. Note that the first 3 decimals are identical.

Adding to 1002000021 its reverse (1200002001), we get a palindrome (2202002022).

The spelling of 1002000021 in words is "one billion, two million, twenty-one", and thus it is an aban number and an uban number.