920807921 has 16 divisors (see below), whose sum is σ = 1050347520. Its totient is φ = 799056720.

The previous prime is 920807917. The next prime is 920807939. The reversal of 920807921 is 129708029.

It is not a de Polignac number, because 920807921 - 2² = 920807917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (920807821) 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 15 ways as a sum of consecutive naturals, for example, 128840 + ... + 135798.

It is an arithmetic number, because the mean of its divisors is an integer number (65646720).

Almost surely, 2^920807921 is an apocalyptic number.

It is an amenable number.

920807921 is a deficient number, since it is larger than the sum of its proper divisors (129539599).

920807921 is a wasteful number, since it uses less digits than its factorization.

920807921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7516.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 920807921 is about 30344.8170368516. The cubic root of 920807921 is about 972.8734439845.

It can be divided in two parts, 92080 and 7921, that added together give a palindrome (100001).

The spelling of 920807921 in words is "nine hundred twenty million, eight hundred seven thousand, nine hundred twenty-one".