137868921397 has 4 divisors (see below), whose sum is σ = 138460633740. Its totient is φ = 137277209056.

The previous prime is 137868921383. The next prime is 137868921427. The reversal of 137868921397 is 793129868731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 793129868731 = 95801 ⋅8278931.

It can be written as a sum of positive squares in 2 ways, for example, as 9883143396 + 127985778001 = 99414^2 + 357751^2 .

It is a cyclic number.

It is not a de Polignac number, because 137868921397 - 2¹⁵ = 137868888629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137868921347) 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, 295855822 + ... + 295856287.

It is an arithmetic number, because the mean of its divisors is an integer number (34615158435).

Almost surely, 2^137868921397 is an apocalyptic number.

It is an amenable number.

137868921397 is a deficient number, since it is larger than the sum of its proper divisors (591712343).

137868921397 is an equidigital number, since it uses as much as digits as its factorization.

137868921397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591712342.

The product of its digits is 27433728, while the sum is 64.

The spelling of 137868921397 in words is "one hundred thirty-seven billion, eight hundred sixty-eight million, nine hundred twenty-one thousand, three hundred ninety-seven".