137147991 has 4 divisors (see below), whose sum is σ = 182863992. Its totient is φ = 91431992.

The previous prime is 137147977. The next prime is 137148013. The reversal of 137147991 is 199741731.

137147991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 137147991 - 2¹⁰ = 137146967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137147971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22857996 + ... + 22858001.

It is an arithmetic number, because the mean of its divisors is an integer number (45715998).

Almost surely, 2^137147991 is an apocalyptic number.

137147991 is a deficient number, since it is larger than the sum of its proper divisors (45716001).

137147991 is an equidigital number, since it uses as much as digits as its factorization.

137147991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45716000.

The product of its digits is 47628, while the sum is 42.

The square root of 137147991 is about 11711.0200665869. The cubic root of 137147991 is about 515.6992305546.

The spelling of 137147991 in words is "one hundred thirty-seven million, one hundred forty-seven thousand, nine hundred ninety-one".