1009200021 has 16 divisors (see below), whose sum is σ = 1352269824. Its totient is φ = 669474864.

The previous prime is 1009200013. The next prime is 1009200047. The reversal of 1009200021 is 1200029001.

It is a happy number.

It is not a de Polignac number, because 1009200021 - 2³ = 1009200013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1009200001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 696720 + ... + 698166.

It is an arithmetic number, because the mean of its divisors is an integer number (84516864).

Almost surely, 2^1009200021 is an apocalyptic number.

It is an amenable number.

1009200021 is a deficient number, since it is larger than the sum of its proper divisors (343069803).

1009200021 is a wasteful number, since it uses less digits than its factorization.

1009200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2440.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1009200021 is about 31767.9086658219. The cubic root of 1009200021 is about 1003.0573169539.

Adding to 1009200021 its reverse (1200029001), we get a palindrome (2209229022).

The spelling of 1009200021 in words is "one billion, nine million, two hundred thousand, twenty-one".