191661648 has 20 divisors (see below), whose sum is σ = 495126048. Its totient is φ = 63887200.

The previous prime is 191661647. The next prime is 191661649. The reversal of 191661648 is 846166191.

It is an interprime number because it is at equal distance from previous prime (191661647) and next prime (191661649).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191661643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1996428 + ... + 1996523.

Almost surely, 2^191661648 is an apocalyptic number.

It is an amenable number.

191661648 is an abundant number, since it is smaller than the sum of its proper divisors (303464400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191661648 is a wasteful number, since it uses less digits than its factorization.

191661648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3992962 (or 3992956 counting only the distinct ones).

The product of its digits is 62208, while the sum is 42.

The square root of 191661648 is about 13844.1918507365. The cubic root of 191661648 is about 576.5607482897.

The spelling of 191661648 in words is "one hundred ninety-one million, six hundred sixty-one thousand, six hundred forty-eight".