1561568976 has 160 divisors (see below), whose sum is σ = 4908435840. Its totient is φ = 471398400.

The previous prime is 1561568963. The next prime is 1561568977. The reversal of 1561568976 is 6798651651.

1561568976 is a `hidden beast` number, since 1 + 5 + 6 + 1 + 568 + 9 + 76 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561568977) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1772056 + ... + 1772936.

It is an arithmetic number, because the mean of its divisors is an integer number (30677724).

Almost surely, 2^1561568976 is an apocalyptic number.

1561568976 is a gapful number since it is divisible by the number (16) 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 1561568976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2454217920).

1561568976 is an abundant number, since it is smaller than the sum of its proper divisors (3346866864).

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

1561568976 is a wasteful number, since it uses less digits than its factorization.

1561568976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1282 (or 1270 counting only the distinct ones).

The product of its digits is 2721600, while the sum is 54.

The square root of 1561568976 is about 39516.6923717054. The cubic root of 1561568976 is about 1160.1666863124.

The spelling of 1561568976 in words is "one billion, five hundred sixty-one million, five hundred sixty-eight thousand, nine hundred seventy-six".