191506139 has 24 divisors (see below), whose sum is σ = 224399808. Its totient is φ = 162035840.

The previous prime is 191506129. The next prime is 191506157. The reversal of 191506139 is 931605191.

It is not a de Polignac number, because 191506139 - 2⁴ = 191506123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 191506099 and 191506108.

It is not an unprimeable number, because it can be changed into a prime (191506129) 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, 339872 + ... + 340434.

It is an arithmetic number, because the mean of its divisors is an integer number (9349992).

Almost surely, 2^191506139 is an apocalyptic number.

191506139 is a deficient number, since it is larger than the sum of its proper divisors (32893669).

191506139 is a wasteful number, since it uses less digits than its factorization.

191506139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 715 (or 698 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 35.

The square root of 191506139 is about 13838.5743124066. The cubic root of 191506139 is about 576.4047709087.

The spelling of 191506139 in words is "one hundred ninety-one million, five hundred six thousand, one hundred thirty-nine".