820061550 has 480 divisors, whose sum is σ = 3000879360. Its totient is φ = 162993600.

The previous prime is 820061533. The next prime is 820061551. The reversal of 820061550 is 55160028.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820061551) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 35654839 + ... + 35654861.

It is an arithmetic number, because the mean of its divisors is an integer number (6251832).

Almost surely, 2^820061550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820061550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1500439680).

820061550 is an abundant number, since it is smaller than the sum of its proper divisors (2180817810).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

820061550 is a wasteful number, since it uses less digits than its factorization.

820061550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83 (or 51 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 820061550 is about 28636.7168160039. The cubic root of 820061550 is about 936.0135805064.

The spelling of 820061550 in words is "eight hundred twenty million, sixty-one thousand, five hundred fifty".