1561967680 has 112 divisors (see below), whose sum is σ = 4577852160. Its totient is φ = 494327808.

The previous prime is 1561967669. The next prime is 1561967681. The reversal of 1561967680 is 867691651.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is not an unprimeable number, because it can be changed into a prime (1561967681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2301 + ... + 55939.

It is an arithmetic number, because the mean of its divisors is an integer number (40873680).

Almost surely, 2^1561967680 is an apocalyptic number.

1561967680 is a gapful number since it is divisible by the number (10) 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 1561967680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2288926080).

1561967680 is an abundant number, since it is smaller than the sum of its proper divisors (3015884480).

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

1561967680 is a wasteful number, since it uses less digits than its factorization.

1561967680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53676 (or 53666 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 49.

The square root of 1561967680 is about 39521.7368039412. The cubic root of 1561967680 is about 1160.2654168720.

The spelling of 1561967680 in words is "one billion, five hundred sixty-one million, nine hundred sixty-seven thousand, six hundred eighty".