137185991 has 6 divisors (see below), whose sum is σ = 138040440. Its totient is φ = 136336796.

The previous prime is 137185981. The next prime is 137186003. The reversal of 137185991 is 199581731.

It is not a de Polignac number, because 137185991 - 2⁶ = 137185927 is a prime.

It is a super-2 number, since 2×137185991² = 37639992253304162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137185901) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 25430 + ... + 30348.

It is an arithmetic number, because the mean of its divisors is an integer number (23006740).

Almost surely, 2^137185991 is an apocalyptic number.

137185991 is a deficient number, since it is larger than the sum of its proper divisors (854449).

137185991 is an frugal number, since it uses more digits than its factorization.

137185991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5253 (or 5086 counting only the distinct ones).

The product of its digits is 68040, while the sum is 44.

The square root of 137185991 is about 11712.6423577261. The cubic root of 137185991 is about 515.7468549274.

The spelling of 137185991 in words is "one hundred thirty-seven million, one hundred eighty-five thousand, nine hundred ninety-one".