139561797 has 4 divisors (see below), whose sum is σ = 186082400. Its totient is φ = 93041196.

The previous prime is 139561787. The next prime is 139561801. The reversal of 139561797 is 797165931.

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.

It is not a de Polignac number, because 139561797 - 2⁴ = 139561781 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 (139561787) 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, 23260297 + ... + 23260302.

It is an arithmetic number, because the mean of its divisors is an integer number (46520600).

Almost surely, 2^139561797 is an apocalyptic number.

It is an amenable number.

139561797 is a deficient number, since it is larger than the sum of its proper divisors (46520603).

139561797 is an equidigital number, since it uses as much as digits as its factorization.

139561797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46520602.

The product of its digits is 357210, while the sum is 48.

The square root of 139561797 is about 11813.6275969746. The cubic root of 139561797 is about 518.7070900395.

It can be divided in two parts, 13956 and 1797, that added together give a triangular number (15753 = T₁₇₇).

The spelling of 139561797 in words is "one hundred thirty-nine million, five hundred sixty-one thousand, seven hundred ninety-seven".