490991921 has 8 divisors (see below), whose sum is σ = 561362304. Its totient is φ = 420678720.

The previous prime is 490991911. The next prime is 490991927. The reversal of 490991921 is 129199094.

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

It is a de Polignac number, because none of the positive numbers 2^k-490991921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (490991927) 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, 6041 + ... + 31913.

It is an arithmetic number, because the mean of its divisors is an integer number (70170288).

Almost surely, 2^490991921 is an apocalyptic number.

It is an amenable number.

490991921 is a deficient number, since it is larger than the sum of its proper divisors (70370383).

490991921 is a wasteful number, since it uses less digits than its factorization.

490991921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28591.

The product of its (nonzero) digits is 52488, while the sum is 44.

The square root of 490991921 is about 22158.3375053274. The cubic root of 490991921 is about 788.9051334272.

The spelling of 490991921 in words is "four hundred ninety million, nine hundred ninety-one thousand, nine hundred twenty-one".