139668019 has 4 divisors (see below), whose sum is σ = 139859296. Its totient is φ = 139476744.

The previous prime is 139667977. The next prime is 139668049. The reversal of 139668019 is 910866931.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 139668019 - 2¹³ = 139659827 is a prime.

It is a super-2 number, since 2×139668019² = 39014311062768722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139668049) 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, 94539 + ... + 96004.

It is an arithmetic number, because the mean of its divisors is an integer number (34964824).

Almost surely, 2^139668019 is an apocalyptic number.

139668019 is a deficient number, since it is larger than the sum of its proper divisors (191277).

139668019 is an equidigital number, since it uses as much as digits as its factorization.

139668019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191276.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 139668019 is about 11818.1224820189. The cubic root of 139668019 is about 518.8386545340.

The spelling of 139668019 in words is "one hundred thirty-nine million, six hundred sixty-eight thousand, nineteen".