1561919355 has 20 divisors (see below), whose sum is σ = 2799885792. Its totient is φ = 833023440.

The previous prime is 1561919347. The next prime is 1561919357. The reversal of 1561919355 is 5539191651.

1561919355 is a `hidden beast` number, since 15 + 619 + 19 + 3 + 5 + 5 = 666.

It is not a de Polignac number, because 1561919355 - 2³ = 1561919347 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1561919355.

It is not an unprimeable number, because it can be changed into a prime (1561919357) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1927891 + ... + 1928700.

Almost surely, 2^1561919355 is an apocalyptic number.

1561919355 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1561919355 is a deficient number, since it is larger than the sum of its proper divisors (1237966437).

1561919355 is an equidigital number, since it uses as much as digits as its factorization.

1561919355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3856608 (or 3856599 counting only the distinct ones).

The product of its digits is 182250, while the sum is 45.

The square root of 1561919355 is about 39521.1254267892. The cubic root of 1561919355 is about 1160.2534511091.

The spelling of 1561919355 in words is "one billion, five hundred sixty-one million, nine hundred nineteen thousand, three hundred fifty-five".