1561984245 has 48 divisors (see below), whose sum is σ = 2780331840. Its totient is φ = 810770688.

The previous prime is 1561984241. The next prime is 1561984247. The reversal of 1561984245 is 5424891651.

1561984245 is a `hidden beast` number, since 1 + 5 + 619 + 8 + 4 + 24 + 5 = 666.

It is not a de Polignac number, because 1561984245 - 2² = 1561984241 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 1561984245.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561984241) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 604366 + ... + 606944.

It is an arithmetic number, because the mean of its divisors is an integer number (57923580).

Almost surely, 2^1561984245 is an apocalyptic number.

1561984245 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1561984245 is a deficient number, since it is larger than the sum of its proper divisors (1218347595).

1561984245 is a wasteful number, since it uses less digits than its factorization.

1561984245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2946 (or 2943 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 1561984245 is about 39521.9463716047. The cubic root of 1561984245 is about 1160.2695184781.

The spelling of 1561984245 in words is "one billion, five hundred sixty-one million, nine hundred eighty-four thousand, two hundred forty-five".