820390551 has 16 divisors (see below), whose sum is σ = 1118694240. Its totient is φ = 534584960.

The previous prime is 820390537. The next prime is 820390553. The reversal of 820390551 is 155093028.

820390551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 820390551 - 2¹³ = 820382359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820390553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33181 + ... + 52361.

It is an arithmetic number, because the mean of its divisors is an integer number (69918390).

Almost surely, 2^820390551 is an apocalyptic number.

820390551 is a deficient number, since it is larger than the sum of its proper divisors (298303689).

820390551 is a wasteful number, since it uses less digits than its factorization.

820390551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19506.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 820390551 is about 28642.4606310282. The cubic root of 820390551 is about 936.1387370596.

The spelling of 820390551 in words is "eight hundred twenty million, three hundred ninety thousand, five hundred fifty-one".