921999001 has 32 divisors (see below), whose sum is σ = 1194163200. Its totient is φ = 690742080.

The previous prime is 921998983. The next prime is 921999011. The reversal of 921999001 is 100999129.

It is not a de Polignac number, because 921999001 - 2⁵ = 921998969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (921999011) 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 31 ways as a sum of consecutive naturals, for example, 631210 + ... + 632668.

It is an arithmetic number, because the mean of its divisors is an integer number (37317600).

Almost surely, 2^921999001 is an apocalyptic number.

It is an amenable number.

921999001 is a deficient number, since it is larger than the sum of its proper divisors (272164199).

921999001 is a wasteful number, since it uses less digits than its factorization.

921999001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1789.

The product of its (nonzero) digits is 13122, while the sum is 40.

The square root of 921999001 is about 30364.4364512171. The cubic root of 921999001 is about 973.2927391146.

The spelling of 921999001 in words is "nine hundred twenty-one million, nine hundred ninety-nine thousand, one".