820542901 has 4 divisors (see below), whose sum is σ = 830929600. Its totient is φ = 810156204.

The previous prime is 820542889. The next prime is 820542929. The reversal of 820542901 is 109245028.

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 820542901 - 2⁷ = 820542773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820542941) 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 3 ways as a sum of consecutive naturals, for example, 5193231 + ... + 5193388.

It is an arithmetic number, because the mean of its divisors is an integer number (207732400).

Almost surely, 2^820542901 is an apocalyptic number.

It is an amenable number.

820542901 is a deficient number, since it is larger than the sum of its proper divisors (10386699).

820542901 is a wasteful number, since it uses less digits than its factorization.

820542901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10386698.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 820542901 is about 28645.1200206946. The cubic root of 820542901 is about 936.1966817824.

Adding to 820542901 its reverse (109245028), we get a palindrome (929787929).

The spelling of 820542901 in words is "eight hundred twenty million, five hundred forty-two thousand, nine hundred one".