137878765 has 4 divisors (see below), whose sum is σ = 165454524. Its totient is φ = 110303008.

The previous prime is 137878757. The next prime is 137878781. The reversal of 137878765 is 567878731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 567878731 = 7 ⋅81125533.

It can be written as a sum of positive squares in 2 ways, for example, as 40678884 + 97199881 = 6378^2 + 9859^2 .

It is a cyclic number.

It is not a de Polignac number, because 137878765 - 2³ = 137878757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 13787872 + ... + 13787881.

It is an arithmetic number, because the mean of its divisors is an integer number (41363631).

Almost surely, 2^137878765 is an apocalyptic number.

It is an amenable number.

137878765 is a deficient number, since it is larger than the sum of its proper divisors (27575759).

137878765 is an equidigital number, since it uses as much as digits as its factorization.

137878765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27575758.

The product of its digits is 1975680, while the sum is 52.

The square root of 137878765 is about 11742.1788863907. The cubic root of 137878765 is about 516.6135524079.

The spelling of 137878765 in words is "one hundred thirty-seven million, eight hundred seventy-eight thousand, seven hundred sixty-five".