1961598618 has 96 divisors (see below), whose sum is σ = 5162901120. Its totient is φ = 525450240.

The previous prime is 1961598607. The next prime is 1961598619. The reversal of 1961598618 is 8168951691.

1961598618 is a `hidden beast` number, since 1 + 9 + 6 + 15 + 9 + 8 + 618 = 666.

It is not an unprimeable number, because it can be changed into a prime (1961598619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 600273 + ... + 603531.

It is an arithmetic number, because the mean of its divisors is an integer number (53780220).

Almost surely, 2^1961598618 is an apocalyptic number.

1961598618 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1961598618, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2581450560).

1961598618 is an abundant number, since it is smaller than the sum of its proper divisors (3201302502).

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

1961598618 is a wasteful number, since it uses less digits than its factorization.

1961598618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3572 (or 3569 counting only the distinct ones).

The product of its digits is 933120, while the sum is 54.

The square root of 1961598618 is about 44289.9381123975. The cubic root of 1961598618 is about 1251.8050972178.

The spelling of 1961598618 in words is "one billion, nine hundred sixty-one million, five hundred ninety-eight thousand, six hundred eighteen".