139597217 has 4 divisors (see below), whose sum is σ = 147808836. Its totient is φ = 131385600.

The previous prime is 139597207. The next prime is 139597223. The reversal of 139597217 is 712795931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 712795931 = 269 ⋅2649799.

It can be written as a sum of positive squares in 2 ways, for example, as 93683041 + 45914176 = 9679^2 + 6776^2 .

It is a cyclic number.

It is not a de Polignac number, because 139597217 - 2⁴ = 139597201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139597207) 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, 4105784 + ... + 4105817.

It is an arithmetic number, because the mean of its divisors is an integer number (36952209).

Almost surely, 2^139597217 is an apocalyptic number.

139597217 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

139597217 is a deficient number, since it is larger than the sum of its proper divisors (8211619).

139597217 is an equidigital number, since it uses as much as digits as its factorization.

139597217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8211618.

The product of its digits is 119070, while the sum is 44.

The square root of 139597217 is about 11815.1266180266. The cubic root of 139597217 is about 518.7509679761.

The spelling of 139597217 in words is "one hundred thirty-nine million, five hundred ninety-seven thousand, two hundred seventeen".