1961556480 has 640 divisors, whose sum is σ = 7836998400. Its totient is φ = 461832192.

The previous prime is 1961556473. The next prime is 1961556557. The reversal of 1961556480 is 846551691.

1961556480 is a `hidden beast` number, since 1 + 9 + 6 + 1 + 5 + 564 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 33246691 + ... + 33246749.

It is an arithmetic number, because the mean of its divisors is an integer number (12245310).

Almost surely, 2^1961556480 is an apocalyptic number.

1961556480 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 1961556480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3918499200).

1961556480 is an abundant number, since it is smaller than the sum of its proper divisors (5875441920).

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

1961556480 is a wasteful number, since it uses less digits than its factorization.

1961556480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The square root of 1961556480 is about 44289.4624036012. The cubic root of 1961556480 is about 1251.7961336204.

The spelling of 1961556480 in words is "one billion, nine hundred sixty-one million, five hundred fifty-six thousand, four hundred eighty".