491510121 has 4 divisors (see below), whose sum is σ = 655346832. Its totient is φ = 327673412.

The previous prime is 491510099. The next prime is 491510189. The reversal of 491510121 is 121015194.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 491510121 - 2²⁷ = 357292393 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 491510091 and 491510100.

It is not an unprimeable number, because it can be changed into a prime (491511121) 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 3 ways as a sum of consecutive naturals, for example, 81918351 + ... + 81918356.

It is an arithmetic number, because the mean of its divisors is an integer number (163836708).

Almost surely, 2^491510121 is an apocalyptic number.

It is an amenable number.

491510121 is a deficient number, since it is larger than the sum of its proper divisors (163836711).

491510121 is a wasteful number, since it uses less digits than its factorization.

491510121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163836710.

The product of its (nonzero) digits is 360, while the sum is 24.

The square root of 491510121 is about 22170.0275371953. The cubic root of 491510121 is about 789.1825764871.

The spelling of 491510121 in words is "four hundred ninety-one million, five hundred ten thousand, one hundred twenty-one".