137520391 has 2 divisors, whose sum is σ = 137520392. Its totient is φ = 137520390.

The previous prime is 137520353. The next prime is 137520401. The reversal of 137520391 is 193025731.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137520391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (137520491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68760195 + 68760196.

It is an arithmetic number, because the mean of its divisors is an integer number (68760196).

Almost surely, 2^137520391 is an apocalyptic number.

137520391 is a deficient number, since it is larger than the sum of its proper divisors (1).

137520391 is an equidigital number, since it uses as much as digits as its factorization.

137520391 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5670, while the sum is 31.

The square root of 137520391 is about 11726.9088424870. The cubic root of 137520391 is about 516.1655706778.

The spelling of 137520391 in words is "one hundred thirty-seven million, five hundred twenty thousand, three hundred ninety-one".