6601967981 has 16 divisors (see below), whose sum is σ = 7944768000. Its totient is φ = 5359274928.

The previous prime is 6601967971. The next prime is 6601967993. The reversal of 6601967981 is 1897691066.

It is a de Polignac number, because none of the positive numbers 2^k-6601967981 is a prime.

It is a super-2 number, since 2×6601967981² = 87171962444298432722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6601967951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 558470 + ... + 570168.

It is an arithmetic number, because the mean of its divisors is an integer number (496548000).

Almost surely, 2^6601967981 is an apocalyptic number.

It is an amenable number.

6601967981 is a deficient number, since it is larger than the sum of its proper divisors (1342800019).

6601967981 is a wasteful number, since it uses less digits than its factorization.

6601967981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15968.

The product of its (nonzero) digits is 979776, while the sum is 53.

The square root of 6601967981 is about 81252.4952293774. The cubic root of 6601967981 is about 1875.9638759500.

The spelling of 6601967981 in words is "six billion, six hundred one million, nine hundred sixty-seven thousand, nine hundred eighty-one".