821611413505 has 8 divisors (see below), whose sum is σ = 990606369024. Its totient is φ = 654174015600.

The previous prime is 821611413503. The next prime is 821611413509. The reversal of 821611413505 is 505314116128.

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

It is not a de Polignac number, because 821611413505 - 2¹ = 821611413503 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (821611413503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 389388241 + ... + 389390350.

It is an arithmetic number, because the mean of its divisors is an integer number (123825796128).

Almost surely, 2^821611413505 is an apocalyptic number.

It is an amenable number.

821611413505 is a deficient number, since it is larger than the sum of its proper divisors (168994955519).

821611413505 is a wasteful number, since it uses less digits than its factorization.

821611413505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778778807.

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 821611413505 in words is "eight hundred twenty-one billion, six hundred eleven million, four hundred thirteen thousand, five hundred five".