1961925591 has 8 divisors (see below), whose sum is σ = 2636498944. Its totient is φ = 1297651320.

The previous prime is 1961925587. The next prime is 1961925601. The reversal of 1961925591 is 1955291691.

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

It is not a de Polignac number, because 1961925591 - 2² = 1961925587 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1961925591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1961925521) 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 7 ways as a sum of consecutive naturals, for example, 2574325 + ... + 2575086.

It is an arithmetic number, because the mean of its divisors is an integer number (329562368).

Almost surely, 2^1961925591 is an apocalyptic number.

1961925591 is a deficient number, since it is larger than the sum of its proper divisors (674573353).

1961925591 is a wasteful number, since it uses less digits than its factorization.

1961925591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5149541.

The product of its digits is 218700, while the sum is 48.

The square root of 1961925591 is about 44293.6292371713. The cubic root of 1961925591 is about 1251.8746465681.

The spelling of 1961925591 in words is "one billion, nine hundred sixty-one million, nine hundred twenty-five thousand, five hundred ninety-one".