5661778500 has 504 divisors, whose sum is σ = 21634396056. Its totient is φ = 1290038400.

The previous prime is 5661778483. The next prime is 5661778511. The reversal of 5661778500 is 58771665.

5661778500 is a `hidden beast` number, since 5 + 66 + 17 + 78 + 500 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1235803716 + 4425974784 = 35154^2 + 66528^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 17860342 + ... + 17860658.

It is an arithmetic number, because the mean of its divisors is an integer number (42925389).

Almost surely, 2^5661778500 is an apocalyptic number.

5661778500 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 5661778500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10817198028).

5661778500 is an abundant number, since it is smaller than the sum of its proper divisors (15972617556).

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

5661778500 is a wasteful number, since it uses less digits than its factorization.

5661778500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368 (or 334 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 45.

The square root of 5661778500 is about 75244.7905173508. The cubic root of 5661778500 is about 1782.3143002400.

The spelling of 5661778500 in words is "five billion, six hundred sixty-one million, seven hundred seventy-eight thousand, five hundred".