139681917 has 6 divisors (see below), whose sum is σ = 201762782. Its totient is φ = 93121272.

The previous prime is 139681897. The next prime is 139681937. The reversal of 139681917 is 719186931.

It is an interprime number because it is at equal distance from previous prime (139681897) and next prime (139681937).

It can be written as a sum of positive squares in only one way, i.e., 126765081 + 12916836 = 11259^2 + 3594^2 .

It is a de Polignac number, because none of the positive numbers 2^k-139681917 is a prime.

It is a super-2 number, since 2×139681917² = 39022075873589778, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139681937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7760098 + ... + 7760115.

Almost surely, 2^139681917 is an apocalyptic number.

It is an amenable number.

139681917 is a deficient number, since it is larger than the sum of its proper divisors (62080865).

139681917 is a wasteful number, since it uses less digits than its factorization.

139681917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15520219 (or 15520216 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 139681917 is about 11818.7104626520. The cubic root of 139681917 is about 518.8558633900.

The spelling of 139681917 in words is "one hundred thirty-nine million, six hundred eighty-one thousand, nine hundred seventeen".