137609861 has 4 divisors (see below), whose sum is σ = 138600000. Its totient is φ = 136619724.

The previous prime is 137609833. The next prime is 137609873. The reversal of 137609861 is 168906731.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 168906731 = 7 ⋅24129533.

It is a cyclic number.

It is not a de Polignac number, because 137609861 - 2¹⁰ = 137608837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137609821) 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 in 3 ways as a sum of consecutive naturals, for example, 494861 + ... + 495138.

It is an arithmetic number, because the mean of its divisors is an integer number (34650000).

Almost surely, 2^137609861 is an apocalyptic number.

It is an amenable number.

137609861 is a deficient number, since it is larger than the sum of its proper divisors (990139).

137609861 is an equidigital number, since it uses as much as digits as its factorization.

137609861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990138.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 137609861 is about 11730.7229529983. The cubic root of 137609861 is about 516.2774845590.

The spelling of 137609861 in words is "one hundred thirty-seven million, six hundred nine thousand, eight hundred sixty-one".