191026381 has 8 divisors (see below), whose sum is σ = 235109504. Its totient is φ = 151141680.

The previous prime is 191026379. The next prime is 191026391. The reversal of 191026381 is 183620191.

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 191026381 - 2¹ = 191026379 is a prime.

It is a super-2 number, since 2×191026381² = 72982156475914322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191026321) 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, 1049505 + ... + 1049686.

It is an arithmetic number, because the mean of its divisors is an integer number (29388688).

Almost surely, 2^191026381 is an apocalyptic number.

It is an amenable number.

191026381 is a deficient number, since it is larger than the sum of its proper divisors (44083123).

191026381 is a wasteful number, since it uses less digits than its factorization.

191026381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2099211.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 191026381 is about 13821.2293592140. The cubic root of 191026381 is about 575.9230351849.

The spelling of 191026381 in words is "one hundred ninety-one million, twenty-six thousand, three hundred eighty-one".