1961635904161 has 8 divisors (see below), whose sum is σ = 1962883068800. Its totient is φ = 1960388911440.

The previous prime is 1961635904153. The next prime is 1961635904279. The reversal of 1961635904161 is 1614095361691.

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

It is a cyclic number.

It is not a de Polignac number, because 1961635904161 - 2³ = 1961635904153 is a prime.

It is a super-2 number, since 2×1961635904161² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1961635904099 and 1961635904108.

It is not an unprimeable number, because it can be changed into a prime (1961635905161) 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, 28788550 + ... + 28856608.

It is an arithmetic number, because the mean of its divisors is an integer number (245360383600).

Almost surely, 2^{1961635904161} is an apocalyptic number.

It is an amenable number.

1961635904161 is a deficient number, since it is larger than the sum of its proper divisors (1247164639).

1961635904161 is a wasteful number, since it uses less digits than its factorization.

1961635904161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85959.

The product of its (nonzero) digits is 1049760, while the sum is 52.

The spelling of 1961635904161 in words is "one trillion, nine hundred sixty-one billion, six hundred thirty-five million, nine hundred four thousand, one hundred sixty-one".