1961878109 has 8 divisors (see below), whose sum is σ = 1977528000. Its totient is φ = 1946250432.

The previous prime is 1961878073. The next prime is 1961878169. The reversal of 1961878109 is 9018781691.

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 1961878109 - 2²⁴ = 1945100893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1961878169) 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, 202232 + ... + 211710.

It is an arithmetic number, because the mean of its divisors is an integer number (247191000).

Almost surely, 2^1961878109 is an apocalyptic number.

It is an amenable number.

1961878109 is a deficient number, since it is larger than the sum of its proper divisors (15649891).

1961878109 is a wasteful number, since it uses less digits than its factorization.

1961878109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11107.

The product of its (nonzero) digits is 217728, while the sum is 50.

The square root of 1961878109 is about 44293.0932426264. The cubic root of 1961878109 is about 1251.8645473078.

The spelling of 1961878109 in words is "one billion, nine hundred sixty-one million, eight hundred seventy-eight thousand, one hundred nine".