191015136 has 144 divisors (see below), whose sum is σ = 590453136. Its totient is φ = 58226688.

The previous prime is 191015081. The next prime is 191015137. The reversal of 191015136 is 631510191.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191015137) 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, 610116 + ... + 610428.

It is an arithmetic number, because the mean of its divisors is an integer number (4100369).

Almost surely, 2^191015136 is an apocalyptic number.

191015136 is a gapful number since it is divisible by the number (16) 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 191015136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (295226568).

191015136 is an abundant number, since it is smaller than the sum of its proper divisors (399438000).

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

191015136 is a wasteful number, since it uses less digits than its factorization.

191015136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 505 (or 494 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 27.

The square root of 191015136 is about 13820.8225514982. The cubic root of 191015136 is about 575.9117341601.

The spelling of 191015136 in words is "one hundred ninety-one million, fifteen thousand, one hundred thirty-six".