861777450 has 144 divisors (see below), whose sum is σ = 2381517216. Its totient is φ = 223344000.

The previous prime is 861777419. The next prime is 861777451. The reversal of 861777450 is 54777168.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 861777396 and 861777405.

It is not an unprimeable number, because it can be changed into a prime (861777451) 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 71 ways as a sum of consecutive naturals, for example, 3045009 + ... + 3045291.

It is an arithmetic number, because the mean of its divisors is an integer number (16538314).

Almost surely, 2^861777450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861777450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1190758608).

861777450 is an abundant number, since it is smaller than the sum of its proper divisors (1519739766).

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

861777450 is a wasteful number, since it uses less digits than its factorization.

861777450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469 (or 461 counting only the distinct ones).

The product of its (nonzero) digits is 329280, while the sum is 45.

The square root of 861777450 is about 29356.0462256074. The cubic root of 861777450 is about 951.6232451292.

The spelling of 861777450 in words is "eight hundred sixty-one million, seven hundred seventy-seven thousand, four hundred fifty".