1961942973681 has 8 divisors (see below), whose sum is σ = 2706128239680. Its totient is φ = 1262859845072.

The previous prime is 1961942973559. The next prime is 1961942973839. The reversal of 1961942973681 is 1863792491691.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1961942973681 is a prime.

It is a super-2 number, since 2×1961942973681² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1961942974681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11275534245 + ... + 11275534418.

It is an arithmetic number, because the mean of its divisors is an integer number (338266029960).

Almost surely, 2^{1961942973681} is an apocalyptic number.

It is an amenable number.

1961942973681 is a deficient number, since it is larger than the sum of its proper divisors (744185265999).

1961942973681 is a wasteful number, since it uses less digits than its factorization.

1961942973681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22551068695.

The product of its digits is 35271936, while the sum is 66.

The spelling of 1961942973681 in words is "one trillion, nine hundred sixty-one billion, nine hundred forty-two million, nine hundred seventy-three thousand, six hundred eighty-one".