561777890 has 16 divisors (see below), whose sum is σ = 1014395832. Its totient is φ = 224001024.

The previous prime is 561777863. The next prime is 561777901. The reversal of 561777890 is 98777165.

It can be written as a sum of positive squares in 4 ways, for example, as 315382081 + 246395809 = 17759^2 + 15697^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 85439 + ... + 91778.

Almost surely, 2^561777890 is an apocalyptic number.

561777890 is a deficient number, since it is larger than the sum of its proper divisors (452617942).

561777890 is a wasteful number, since it uses less digits than its factorization.

561777890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177541.

The product of its (nonzero) digits is 740880, while the sum is 50.

The square root of 561777890 is about 23701.8541468806. The cubic root of 561777890 is about 825.1284232281.

The spelling of 561777890 in words is "five hundred sixty-one million, seven hundred seventy-seven thousand, eight hundred ninety".