820208655493 has 4 divisors (see below), whose sum is σ = 855869901408. Its totient is φ = 784547409580.

The previous prime is 820208655491. The next prime is 820208655499. The reversal of 820208655493 is 394556802028.

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 820208655493 - 2¹ = 820208655491 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 820208655493.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820208655491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17830622923 + ... + 17830622968.

It is an arithmetic number, because the mean of its divisors is an integer number (213967475352).

Almost surely, 2^820208655493 is an apocalyptic number.

It is an amenable number.

820208655493 is a deficient number, since it is larger than the sum of its proper divisors (35661245915).

820208655493 is a wasteful number, since it uses less digits than its factorization.

820208655493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35661245914.

The product of its (nonzero) digits is 4147200, while the sum is 52.

The spelling of 820208655493 in words is "eight hundred twenty billion, two hundred eight million, six hundred fifty-five thousand, four hundred ninety-three".