191621385 has 24 divisors (see below), whose sum is σ = 342860544. Its totient is φ = 98900640.

The previous prime is 191621377. The next prime is 191621387. The reversal of 191621385 is 583126191.

It is not a de Polignac number, because 191621385 - 2³ = 191621377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (191621387) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 67287 + ... + 70076.

It is an arithmetic number, because the mean of its divisors is an integer number (14285856).

Almost surely, 2^191621385 is an apocalyptic number.

191621385 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

191621385 is a deficient number, since it is larger than the sum of its proper divisors (151239159).

191621385 is a wasteful number, since it uses less digits than its factorization.

191621385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137405 (or 137402 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 191621385 is about 13842.7376266402. The cubic root of 191621385 is about 576.5203721174.

The spelling of 191621385 in words is "one hundred ninety-one million, six hundred twenty-one thousand, three hundred eighty-five".