1961617680 has 240 divisors, whose sum is σ = 7224287616. Its totient is φ = 473057280.

The previous prime is 1961617667. The next prime is 1961617699. The reversal of 1961617680 is 867161691.

1961617680 is a `hidden beast` number, since 19 + 616 + 17 + 6 + 8 + 0 = 666.

1961617680 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (240).

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 47 ways as a sum of consecutive naturals, for example, 1844829 + ... + 1845891.

Almost surely, 2^1961617680 is an apocalyptic number.

1961617680 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 1961617680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3612143808).

1961617680 is an abundant number, since it is smaller than the sum of its proper divisors (5262669936).

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

1961617680 is a wasteful number, since it uses less digits than its factorization.

1961617680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326 (or 1317 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 1961617680 is about 44290.1533074791. The cubic root of 1961617680 is about 1251.8091520452.

It can be divided in two parts, 196161 and 7680, that added together give a triangular number (203841 = T₆₃₈).

The spelling of 1961617680 in words is "one billion, nine hundred sixty-one million, six hundred seventeen thousand, six hundred eighty".