1961991360 has 252 divisors, whose sum is σ = 7850782368. Its totient is φ = 448422912.

The previous prime is 1961991313. The next prime is 1961991371. The reversal of 1961991360 is 631991691.

1961991360 is a `hidden beast` number, since 19 + 619 + 9 + 13 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (252).

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 134169 + ... + 148071.

Almost surely, 2^1961991360 is an apocalyptic number.

1961991360 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 1961991360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3925391184).

1961991360 is an abundant number, since it is smaller than the sum of its proper divisors (5888791008).

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

1961991360 is a wasteful number, since it uses less digits than its factorization.

1961991360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13940 (or 13920 counting only the distinct ones).

The product of its (nonzero) digits is 78732, while the sum is 45.

The square root of 1961991360 is about 44294.3716514864. The cubic root of 1961991360 is about 1251.8886351420. Note that the first 3 decimals are identical.

The spelling of 1961991360 in words is "one billion, nine hundred sixty-one million, nine hundred ninety-one thousand, three hundred sixty".