137787971 has 2 divisors, whose sum is σ = 137787972. Its totient is φ = 137787970.

The previous prime is 137787919. The next prime is 137787977. The reversal of 137787971 is 179787731.

It is a strong prime.

It is an emirp because it is prime and its reverse (179787731) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-137787971 is a prime.

It is not a weakly prime, because it can be changed into another prime (137787977) 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 as a sum of consecutive naturals, namely, 68893985 + 68893986.

It is an arithmetic number, because the mean of its divisors is an integer number (68893986).

Almost surely, 2^137787971 is an apocalyptic number.

137787971 is a deficient number, since it is larger than the sum of its proper divisors (1).

137787971 is an equidigital number, since it uses as much as digits as its factorization.

137787971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 518616, while the sum is 50.

The square root of 137787971 is about 11738.3121018313. The cubic root of 137787971 is about 516.5001297923.

The spelling of 137787971 in words is "one hundred thirty-seven million, seven hundred eighty-seven thousand, nine hundred seventy-one".