561638953778 has 32 divisors (see below), whose sum is σ = 986794541568. Its totient is φ = 234742636800.

The previous prime is 561638953763. The next prime is 561638953783. The reversal of 561638953778 is 877359836165.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1333883 + ... + 1703678.

It is an arithmetic number, because the mean of its divisors is an integer number (30837329424).

Almost surely, 2^561638953778 is an apocalyptic number.

561638953778 is a deficient number, since it is larger than the sum of its proper divisors (425155587790).

561638953778 is a wasteful number, since it uses less digits than its factorization.

561638953778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3037898.

The product of its digits is 228614400, while the sum is 68.

The spelling of 561638953778 in words is "five hundred sixty-one billion, six hundred thirty-eight million, nine hundred fifty-three thousand, seven hundred seventy-eight".