191403920 has 80 divisors (see below), whose sum is σ = 464113152. Its totient is φ = 73328640.

The previous prime is 191403917. The next prime is 191403931. The reversal of 191403920 is 29304191.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 279899 + ... + 280581.

Almost surely, 2^191403920 is an apocalyptic number.

191403920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191403920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (232056576).

191403920 is an abundant number, since it is smaller than the sum of its proper divisors (272709232).

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

191403920 is a wasteful number, since it uses less digits than its factorization.

191403920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 840 (or 834 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 191403920 is about 13834.8805560438. The cubic root of 191403920 is about 576.3021980343.

The spelling of 191403920 in words is "one hundred ninety-one million, four hundred three thousand, nine hundred twenty".