139497973 has 2 divisors, whose sum is σ = 139497974. Its totient is φ = 139497972.

The previous prime is 139497959. The next prime is 139497989. The reversal of 139497973 is 379794931.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136375684 + 3122289 = 11678^2 + 1767^2 .

It is a cyclic number.

It is not a de Polignac number, because 139497973 - 2²¹ = 137400821 is a prime.

It is a super-2 number, since 2×139497973² = 38919368942217458, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 139497973.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139497773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69748986 + 69748987.

It is an arithmetic number, because the mean of its divisors is an integer number (69748987).

Almost surely, 2^139497973 is an apocalyptic number.

It is an amenable number.

139497973 is a deficient number, since it is larger than the sum of its proper divisors (1).

139497973 is an equidigital number, since it uses as much as digits as its factorization.

139497973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1285956, while the sum is 52.

The square root of 139497973 is about 11810.9260009535. The cubic root of 139497973 is about 518.6280067709.

The spelling of 139497973 in words is "one hundred thirty-nine million, four hundred ninety-seven thousand, nine hundred seventy-three".