137981691 has 8 divisors (see below), whose sum is σ = 204417360. Its totient is φ = 91987776.

The previous prime is 137981677. The next prime is 137981693. The reversal of 137981691 is 196189731.

It is not a de Polignac number, because 137981691 - 2⁵ = 137981659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (137981693) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2555190 + ... + 2555243.

It is an arithmetic number, because the mean of its divisors is an integer number (25552170).

Almost surely, 2^137981691 is an apocalyptic number.

137981691 is a deficient number, since it is larger than the sum of its proper divisors (66435669).

137981691 is an equidigital number, since it uses as much as digits as its factorization.

137981691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5110442 (or 5110436 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 137981691 is about 11746.5608158303. The cubic root of 137981691 is about 516.7420704840.

The spelling of 137981691 in words is "one hundred thirty-seven million, nine hundred eighty-one thousand, six hundred ninety-one".