491551157 has 8 divisors (see below), whose sum is σ = 494291616. Its totient is φ = 488818512.

The previous prime is 491551153. The next prime is 491551187. The reversal of 491551157 is 751155194.

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

It is a cyclic number.

It is not a de Polignac number, because 491551157 - 2² = 491551153 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 491551157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491551153) 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 7 ways as a sum of consecutive naturals, for example, 158738 + ... + 161804.

It is an arithmetic number, because the mean of its divisors is an integer number (61786452).

Almost surely, 2^491551157 is an apocalyptic number.

It is an amenable number.

491551157 is a deficient number, since it is larger than the sum of its proper divisors (2740459).

491551157 is a wasteful number, since it uses less digits than its factorization.

491551157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3907.

The product of its digits is 31500, while the sum is 38.

The square root of 491551157 is about 22170.9530016190. The cubic root of 491551157 is about 789.2045387306.

The spelling of 491551157 in words is "four hundred ninety-one million, five hundred fifty-one thousand, one hundred fifty-seven".