491645309553 has 32 divisors (see below), whose sum is σ = 760312110720. Its totient is φ = 313677074880.

The previous prime is 491645309531. The next prime is 491645309563. The reversal of 491645309553 is 355903546194.

491645309553 is a `hidden beast` number, since 4 + 9 + 16 + 4 + 530 + 95 + 5 + 3 = 666.

It is not a de Polignac number, because 491645309553 - 2¹⁸ = 491645047409 is a prime.

It is a super-2 number, since 2×491645309553² (a number of 24 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 491645309553.

It is not an unprimeable number, because it can be changed into a prime (491645309563) 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, 3972975 + ... + 4094852.

It is an arithmetic number, because the mean of its divisors is an integer number (23759753460).

Almost surely, 2^491645309553 is an apocalyptic number.

It is an amenable number.

491645309553 is a deficient number, since it is larger than the sum of its proper divisors (268666801167).

491645309553 is a wasteful number, since it uses less digits than its factorization.

491645309553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8067934 (or 8067928 counting only the distinct ones).

The product of its (nonzero) digits is 8748000, while the sum is 54.

The spelling of 491645309553 in words is "four hundred ninety-one billion, six hundred forty-five million, three hundred nine thousand, five hundred fifty-three".