1561778853 has 32 divisors (see below), whose sum is σ = 2288332800. Its totient is φ = 943747200.

The previous prime is 1561778851. The next prime is 1561778909. The reversal of 1561778853 is 3588771651.

It is not a de Polignac number, because 1561778853 - 2¹ = 1561778851 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1561778796 and 1561778805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561778851) 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 31 ways as a sum of consecutive naturals, for example, 152298 + ... + 162228.

It is an arithmetic number, because the mean of its divisors is an integer number (71510400).

Almost surely, 2^1561778853 is an apocalyptic number.

It is an amenable number.

1561778853 is a deficient number, since it is larger than the sum of its proper divisors (726553947).

1561778853 is a wasteful number, since it uses less digits than its factorization.

1561778853 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10073.

The product of its digits is 1411200, while the sum is 51.

The square root of 1561778853 is about 39519.3478311573. The cubic root of 1561778853 is about 1160.2186599790.

The spelling of 1561778853 in words is "one billion, five hundred sixty-one million, seven hundred seventy-eight thousand, eight hundred fifty-three".