5816501620821 has 12 divisors (see below), whose sum is σ = 8401636832940. Its totient is φ = 3877656956160.

The previous prime is 5816501620793. The next prime is 5816501620843. The reversal of 5816501620821 is 1280261056185.

5816501620821 is a `hidden beast` number, since 5 + 8 + 1 + 6 + 501 + 62 + 0 + 82 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 4148916798321 + 1667584822500 = 2036889^2 + 1291350^2 .

It is not a de Polignac number, because 5816501620821 - 2⁵ = 5816501620789 is a prime.

It is a super-2 number, since 2×5816501620821² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5816501620021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3815491 + ... + 5117711.

It is an arithmetic number, because the mean of its divisors is an integer number (700136402745).

Almost surely, 2^{5816501620821} is an apocalyptic number.

It is an amenable number.

5816501620821 is a deficient number, since it is larger than the sum of its proper divisors (2585135212119).

5816501620821 is a wasteful number, since it uses less digits than its factorization.

5816501620821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1798516 (or 1798513 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 45.

The spelling of 5816501620821 in words is "five trillion, eight hundred sixteen billion, five hundred one million, six hundred twenty thousand, eight hundred twenty-one".