1561989312 has 224 divisors, whose sum is σ = 5106984960. Its totient is φ = 464901120.

The previous prime is 1561989269. The next prime is 1561989313. The reversal of 1561989312 is 2139891651.

1561989312 is a `hidden beast` number, since 1 + 561 + 9 + 89 + 3 + 1 + 2 = 666.

It is a super-2 number, since 2×1561989312² = 4879621221604466688, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561989313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 695263 + ... + 697505.

It is an arithmetic number, because the mean of its divisors is an integer number (22799040).

Almost surely, 2^1561989312 is an apocalyptic number.

1561989312 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561989312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2553492480).

1561989312 is an abundant number, since it is smaller than the sum of its proper divisors (3544995648).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561989312 is a wasteful number, since it uses less digits than its factorization.

1561989312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2308 (or 2292 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 1561989312 is about 39522.0104751770. The cubic root of 1561989312 is about 1160.2707730958.

The spelling of 1561989312 in words is "one billion, five hundred sixty-one million, nine hundred eighty-nine thousand, three hundred twelve".